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Effects of immediacy of feedback and level of aspiration statements on learning tasks for delinquent youngsters.

The performance of institutionalized delinquent youngsters on paired associate learning tasks was investigated to determine whether level of aspiration (LOA) statements were associated with improved performance under varying feedback conditions. The effects of the feedback conditions were also examined. Forty-eight male adolescents were randomly assigned to the following six treatment conditions: (1) Delayed Feedback, (2) Delayed Feedback with LOA, (3) Immediate Feedback, (4) Immediate Feedback with LOA, (5) No Feedback, (6) No Feedback with LOA. The LOA conditions produced significantly better performance than did the no-LOA conditions. Implications for curricular intervention are discussed.

Achievement↗

Epidemiologic risk factors for periodontal attachment loss among adults in the United States.

OBJECTIVES: The objective of this study was to identify variables related to periodontal loss of attachment (LOA). MATERIALS AND METHODS: The study population consisted of a nationally representative sample of 12,325 US adults who participated in the National Health and Nutrition Examination Survey III. The analyses used survey multinomial logistic regression to account for the complex survey design. RESULTS: The adjusted odds ratio for a mean LOA of 3 mm or more associated with current smoking was 18.55 (95% CI 9.44-36.45) among 20-49-year olds. Among those aged 50 years or more, the odds ratio for a mean LOA of 4 mm or more was 25.64 (13.04-50.40). Prior smoking, untreated decayed surfaces (on both person and site levels), and male gender were also associated with LOA. There was no excess risk observed among non-Hispanic blacks or Mexican-Americans. The adjusted population attributable fractions due to current smoking were 60% for persons aged 20-49 with the worst 10% of LOA (1.58 mm or more), and 47% for those aged 50 plus (LOA of 3.39 mm or more). CONCLUSION: These results support earlier findings regarding the central role of cigarette smoking in the etiology of periodontal loss of attachment, a role due in large part to the substantial relationship between smoking and severe periodontal disease.

Adult↗

Human occult loiasis: field evaluation of a nested polymerase chain reaction assay for the detection of occult infection.

A nested polymerase chain reaction (nested PCR) assay, targeted on the repeat 3 region (15r3) of the gene coding for a Loa loa 15 kD polyprotein, was developed to detect L. loa infection. The assay has a sensitivity of 95% and is 100% specific with regard to sympatric filarial parasites: Mansonella perstans, Onchocerca volvulus and Wuchereria bancrofti. In this field study in a mixed filarial (L. loa and M. perstans) endemic region of Gabon, 157 L. loa amicrofilaraemic blood samples (AMF; diagnosed by leucoconcentration followed by standard microscopic examination) from the residents from four villages were screened by the 15r3-nested PCR assay. The assay detected 106 occult infected subjects among the 157 AMF individuals (68%), including 59 of 87 adults (68%) and 47 of 70 children (67%). In each village the prevalence of occult infection was, respectively, 38%, 52%, 79% and 80% for Moyabi, Djoutou, N'djokaye and Okoumbi. The annual transmission potential (ATP) of loiasis has been estimated to be 250 infective larvae (L 3) per man per year for Moyabi and Djoutou, 1800 for N'djokaye and 433000 L3/man/year for Okoumbi. This implies a correlation between occult infection of loiasis and the intensity of transmission. By contrast, the prevalence of L. loa microfilariae was 21% for Okoumbi, 22%, for N'djokaye and 19% for Djoutou and Moyabi. These results show that the prevalence of loiasis in this region of Gabon is higher than previously described by standard microscopic examination and that the application of this assay will be significant in the development of control strategies for loiasis.

Adolescent↗

Estrogen variation and resting left ventricular structure and function in young healthy females.

PURPOSE: A potential confounding factor in the interpretation of left ventricular (LV) structural and functional data in female subjects could be menstrual phase or contraceptive use upon assessment. To date no study has addressed this issue. METHODS: Seventeen eumenorrheic (EU; mean +/- SD age = 21 +/- 3 yr) and 14 combined-oral contraceptive pill-using (COC: mean +/- SD age = 21 +/- 3 yr) females volunteered to participate. The EU had stable menstrual cycles and the COC had all been using the same pill preparation for a minimum of 6 months. Echocardiographic examinations occurred during the mid-follicular phase and mid-luteal phases in the EU and during mid-consumption and mid-end of withdrawal in the COC. LV structure and function were assessed using M-mode and pulsed-wave Doppler echocardiography. Data were compared via Student t-tests and limits of agreement (LoA) were calculated. RESULTS: Structure and function did not significantly differ between phases of the menstrual cycle or between consumption and withdrawal of oral contraception (P > 0.05). However, there was considerable variance in the LoA between variables. Smaller LoA were reported for those variables directly measured from echocardiograms compared with those from derived data. For example, in a measured variable such as LV internal dimension in diastole, the LoA data represented a variation of +/- 0.4 mm (+/- 1%) between phases. Conversely, data for LV mass, a derived variable, reported LoA values of +/- 15 g (10%) between phases. The LoA were consistent between EU and COC. Variation in both measured and derived variables were within, or close to, accepted limits of measurement or biological error. CONCLUSION: It would seem that in studies assessing LV structure and function in women the influence of menstrual phase or oral contraceptive use is of minor significance.

Adult↗

Ocular component measurement using the Zeiss IOLMaster.

PURPOSE: Axial length is traditionally measured using A-scan ultrasound. The IOLMaster is a new instrument that uses partial coherence interferometry to measure axial length. We compared the repeatability of these techniques for both an experienced and an inexperienced observer, the agreement between the two techniques, and the effect of cycloplegia on IOLMaster measurements. METHODS: Five measurements of axial length and three measurements of anterior chamber depth were taken with the IOLMaster in two sessions separated by 1 to 12 days in 20 young adults. The two examiners each took measurements, and the subject was then cyclopleged with 1% tropicamide. The IOLMaster readings were then repeated by both examiners, followed by five ultrasound readings. Repeatability was evaluated by calculating the difference between measurements from the two sessions. The mean and standard deviation of these differences was then used to determine the 95% limits of agreement (LoA) for each technique. In addition, the agreement between the IOLMaster and ultrasound was assessed, along with the effect of cycloplegia on IOLMaster readings. RESULTS: The IOLMaster was more repeatable than ultrasound. For axial length, the 95% LoA were -0.11 to +0.07 mm, -0.06 to +0.05 mm, and -0.25 to +0.35 mm, for noncycloplegic IOLMaster, cycloplegic IOLMaster, and ultrasound, respectively. The two instruments showed modest agreement with each other (mean difference, +0.12 mm; 95% LoA, -0.39 to +0.64 mm; p > 0.0125). Cycloplegia had no significant effect on IOLMaster axial length measurements. The 95% LoA for anterior chamber depth measurement were -0.11 to +0.18 mm, -0.06 to +0.04 mm, and -0.19 to +0.21 mm, for noncycloplegic IOLMaster, cycloplegic IOLMaster, and ultrasound, respectively. The IOLMaster gave significantly longer anterior chamber depths than ultrasound (mean, +0.18 mm; 95% LoA, -0.02 to +0.37 mm; p < 0.0125), and cycloplegia produced significantly deeper anterior chamber depths using the IOLMaster (mean, +0.12 +/- 0.09 mm; 95% LoA, -0.05 to +0.29 mm; t = 6.17; p < 0.001). The experienced observer's measurements were more repeatable than the inexperienced observer's for ultrasound, but not for the IOLMaster. CONCLUSIONS: The superior repeatability of the IOLMaster suggests that it should become the standard for axial length measurement. The 95% limits of agreement for the cycloplegic measurements correspond to a change in refractive error of +/-0.12 D.

Adult↗

[Neutral position magnetic resonance imaging for diagnosis of Hirayama disease].

OBJECTIVE: To investigate the sensitivity and specificity of neutral position cervical MRI in the diagnosis of Hirayama disease. METHODS: Neutral position cervical MRI of 18 patients and 31 young normal control subjects were evaluated for localized lower cervical cord atrophy, asymmetric cord flattening, abnormal cervical curvature, loss of attachment (LOA) and noncompressed intramedullary high signal intensity on T2-weighted MRI. The difference in frequency of these findings between the control and patient groups was examined by means of the x' test. The sensitivity and specificity of these MRI findings in the diagnosis of Hirayama disease were calculated. Multiple logistic regression was performed to explore the relationship with Hirayama disease. RESULTS: (1) There was significant difference in the frequency of localized lower cervical cord atrophy, asymmetric cord flattening and LOA between the patient and control groups (P < 0.05). (2) After adjusting localized lower cervical cord atrophy, asymmetric cord flattening, abnormal cervical curvature and LOA, the analysis showed that LOA was the only significantly important predictor of the disease, with odds ratio of 49.38 (95% CI: 3.97 - 614.73). Sensitivity and specificity of LOA were 88.0% and 90.6% respectively. (3) Sensitivity and specificity of localized lower cervical cord atrophy were 84.6% and 80.6%. Sensitivity and specificity of asymmetric cord flattening were 87.5% and 73.2%, but our case-control study did not fine any significant association between localized lower cervical cord atrophy and Hirayama disease and also between asymmetric cord flattening and Hirayama disease. CONCLUSIONS: LOA between posterior dural sac and subjacent lamina is the most valuable finding in the diagnosis of Hirayama disease at neutral position MR imaging.

Adolescent↗

Haemoparasites of blood donors in Calabar.

The study of haemoparasites in our blood donors revealed the following parasite prevalences: microfilaria (mf) of Loa loa (1.3%); Dipetalonema perstans (15.6%); Loa loa and D. perstans (0.2%), Plasmodium falciparum (3.3%), Plasmodium malariae (1.0%) and a mixture of P. falciparum and P. malariae (0.2%). No trypanosomes were observed in the 480 blood samples screened. There were more cases of D. perstans infection in the 24-30 year age group, indicating their increased exposure frequencies. Matching of ABO blood group and mf infection rates shows that the O blood group has a higher prevalence rate with regard to D. perstans than Loa loa. The B blood group, however, had the highest cumulative % of mf infection (23.4%), but these values are consistent with the preponderance of the various blood groups in the study population. Commercial donors, most of whom come from the less affluent social classes, had higher prevalence rates of mf. It is recommended that blood be properly screened for mf before donation for transfusion. Recipients of infected blood should be followed up so that any consequent infection would be treated immediately.

Adolescent↗

[Circular dichroism of DNA complexes with dyes. III. Effect of latent optical activity and the structure of the complexes].

Circular dichroism anisotropy was studied both theoretically and experimentally for the complexes of DNA and dsRNA with dyes (proflavine, 2,7-di-t-butyl proflavine, "Hoechst-33258") and antibiotics (distamycin A, netropsin and olivomycin). Theoretical analysis showed that general features of CD anisotropy, revealed in the previous studies (CD components--delta epsilon parallel to and delta epsilon perpendicular--are ten times or more bigger than the CD-effect without orientation, and delta epsilon parallel to approximately 2 delta epsilon perpendicular) are due to the existence of a specific effect named "latent" optical activity (LOA). This effect can be observed in many cases of non-chiral symmetrical chromophores if they are oriented. The effect is due to the excitation of an electrical dipole transition and a perpendicular magnetic dipole transition (or quadrupole transition) of a molecule. The amplitude and the sign of the LOA-effect depends on the orientation of the chromophores with respect to the light beam; with a random orientation the mutual compensation of LOA-effects of different chromophores happens and no LOA-effect appears. The analitycal expressions relating the value of LOA-effect of the system with electronical characteristics of the chromophores and the geometrical parametra of their arrangement was obtained. The experimental data obtained for the oriented complexes of DNA and dsRNA with proflavine made it possible to determine an angle between the chromophore and the plane perpendicular to the DNA axis--gamma. For the calf thymus DNA gamma = = + 1.8 +/- 0.4 degrees, for the phage T2 DNA gamma = + 2.2 +/- 0.4 degrees, and for phage f2 dsRNA gamma=--3.5 +/- +/- 0.5 degrees. These results, obtained at relatively low concentrations of the bound proflavine (r approximately 0.01), are in accordance with the intercalating mode of the dye binding. A study of CD anisotropy of DNA complexes with other ligands showed that many different chromophores possess LOA-effect. This phenomenon can be used to obtain both spectroscopic and structural information about the systems similar to those reported here.

Acridines↗

Loiasis: the individual factors associated with the presence of microfilaraemia.

No microfilariae are detectable in a significant percentage of those infected with the filarial worm Loa loa. While the probability of an infected individual becoming microfilaraemic is known to increase with age, the mechanisms underlying this trend are not well understood. Epidemiological data from an endemic village in central Cameroon were therefore explored, in an attempt to determine if, after taking into account any history of filaricidal treatment, the presence of Loa microfilaraemia in an individual was related to his/her gender, age, and/or exposure to the human-infective larvae of the parasite. An index of exposure, based on the monthly transmission potentials of the Chrysops in each of the main types of vegetation in a village and on the activity schedule of each inhabitant of the village, was developed. The results of the data analysis confirm that the acquisition of microfilaraemia is gender-dependent (males generally being more likely to be microfilaraemic than females), and indicate that, in males, a high level of exposure to infective larvae determines the shift from amicrofilaraemic to microfilaraemic status. They also indicate that filaricidal treatments have a long-lasting suppressive effect on Loa microfilaraemia, an observation that may have important implications for any strategy to limit the risk of Loa-associated encephalopathy following ivermectin treatment.

Adolescent↗

[Comparative analysis of 2 diagnostic methods of human loiasis: IgG4 serology and nested PCR].

By evaluating the diagnostic methods developed in our laboratory, the prevalence of loaiosis was estimated among 201 individuals from the province of Haut Ogooué in Gabon using IgG4 serology and nested-PCR. The study showed that the prevalence of loaiosis was higher than that described using standard microscopy. IgG4-based ELISA (Enzyme Linked Immunosorbant Assay) using crude extract of Loa loa microfilariae showed that 80% (35/44) of microfilaraemic individuals (MF') and 56% (88/157) of amicrofilaraemics (AMF) presented antibodies. By contrast, L. loa specific DNA amplified by nested-PCR was detected in all MF and in 68% (106/157) of AMF. Among the 201 samples tested, 95 (47%) gave positive results in both tests. These results indicate that the presence of IgG4 antibodies directed against crude extract of L. loa microfilariae is not linked to the positivity of nested-PCR assay (chi 2 for paired data = 8.78; P < 0.02). We conclude that the PCR assay is more sensitive than the detection of IgG4 antibodies (directed against crude extract of L. loa microfilariae) in detecting loaiosis, and particularly occult loaiosis (infection without circulating microfilariae).

Animals↗

Correlation of central venous and arterial blood gas measurements in mechanically ventilated trauma patients.

HYPOTHESIS: Central venous blood gas (VBG) measurements of pH, PCO2, and base excess can be substituted for the same values obtained from an arterial blood gas (ABG) analysis in mechanically ventilated trauma patients, obviating the need for arterial puncture. DESIGN AND SETTING: Prospective comparison of 99 sets of VBGs and ABGs at a level 1 academic trauma center. PATIENTS: A consecutive sample of 25 trauma patients admitted to the intensive care unit who required mechanical ventilation and had both central venous and arterial catheters. MAIN OUTCOME MEASURES: Pearson correlations and Bland-Altman limits of agreement (LOAs) for pH, PCO2, and base excess values from each set of VBGs and ABGs. RESULTS: When VBG and ABG values were compared, pH had R = 0.92, P<.001, and 95% LOAs of -0.09 to 0.03; PCO2, R = 0.88, P<.001, and 95% LOAs of -2.2 to 10.9; and base excess, R = 0.96, P<.001, and 95% LOAs of -2.2 to 1.8. A receiver operating characteristic curve showed that a central venous PCO2 of 50 mm Hg had 100% sensitivity and 84% specificity for determining significant hypercarbia (arterial PCO2 > 50 mm Hg). CONCLUSIONS: Central venous and arterial PCO2, pH, and base excess values correlate well, but their LOAs represent clinically significant ranges that could affect management. Although VBGs cannot be substituted for ABGs in mechanically ventilated trauma patients during the initial phases of resuscitation, clinically reliable conclusions can be reached with VBG analysis.

Blood Gas Analysis↗

Ondansetron reduces the craving of biologically predisposed alcoholics.

RATIONALE: Early onset alcoholics (EOA) differ from late onset alcoholics (LOA) by having greater serotonergic abnormality, familial history, and a range of antisocial behaviors. Previously, we showed that ondansetron, a selective 5-HT3 antagonist, effectively treated EOA. Proximate motivational drives such as craving could have determined drinking behavior. We therefore investigated whether ondansetron treatment would reduce alcohol craving significantly among EOA. OBJECTIVES: We tested the hypothesis that the craving outcomes of EOA, compared with LOA, would be differentially improved by ondansetron. We also tested the prediction that craving would be significantly correlated with drinking behavior. METHODS: We studied a cohort of 253 out of 321 enrolled alcohol dependent subjects. These 253 subjects were entered into a 1-week lead-in single-blind placebo period followed by 11 weeks of double-blind outpatient treatment. Study design was a 2 (EOA versus LOA)x 4 medication dose (placebo, or ondansetron 1, 4, or 16 microg/kg b.i.d)x 13 (visits) factorial analysis of variance. Craving was measured at each visit using seven visual analogue scales. Subjects received 12 weekly sessions of standardized group cognitive behavioral therapy. RESULTS: Data reduction by factor analysis of the visual analog scale items yielded one dimension, overall craving. Ondansetron 4 microg/kg b.i.d. reduced overall craving significantly among EOA. In contrast, ondansetron (1 microg/kg b.i.d.) increased craving significantly in LOA. Decreased overall craving was positively correlated with reduced drinking and negatively associated with increased abstinence. CONCLUSIONS: Compared with placebo, ondansetron (4 microg/kg b.i.d.) was associated with significant reductions in overall craving in EOA but not LOA, presumably by ameliorating serotonergic abnormality.

Adult↗

Evaluating the use of a portable ultrasound machine to quantify intima-media thickness and flow-mediated dilation: agreement between measurements from two ultrasound machines.

Flow-mediated dilation (FMD) and common carotid intima-media thickness (CIMT) are intermediate endpoints for cardiovascular disease. The purpose of this study was to determine whether a portable ultrasound machine was capable of valid measurements of FMD and CIMT compared with a clinic-based machine under similar conditions. Vascular images were taken on 23 apparently healthy young adults with the portable type and clinic type instruments. The analyses revealed a high level of agreement between the two machines for measurements of mean [corrected] CIMT (mean difference [MD] = -0.025 mm, limits of agreement [LOA] = -0.080, 0.029 mm), maximum [corrected] CIMT (MD = 0.001 mm, LOA = -0.065, 0.065 mm) and FMD measures of brachial diameter (baseline MD = 0.199 mm, LOA = -0.210, 0.608 mm, maximum MD = 0.218 mm, LOA = -0.162, 0.597 mm). Reasonable agreement was found for %FMD measurements (MD = 0.27%, LOA = -4.91, 5.44%). The within-machine coefficient of variation results for mean [corrected] CIMT (5.0%), maximum [corrected] CIMT (4.3%), baseline (6.3%) and maximum (5.4%) brachial diameter and %FMD (30.1%) were comparable with normal within-subject variation. We conclude that the portable ultrasound machine can provide measurements of FMD and CIMT that are highly comparable with measurements obtained from a clinic-based machine under similar clinical conditions.

Adult↗

Heterogeneity in the prevalence and intensity of loiasis in five contrasting bioecological zones in Cameroon.

The prevalence and intensity of loiasis were studied in 4532 individuals selected from 42 villages from 5 contrasting bioecological zones in Cameroon from February to July 2001. The individuals were examined for Loa loa microfilaraemia using the thick blood film method. Loiasis was heterogeneously distributed from one bioecological zone to another. The occurrence of the infection was largely related to environmental factors favouring the breeding of Chrysops vectors. The mean prevalence of infection varied from 0% in the grassland savannah, 6.6% in the deciduous equatorial rainforest, 9.7% in the dense-humid equatorial rainforest, to 33.3% in the forested savannah. Loiasis was totally absent in the grassland savannah. The intensity of loiasis infection (L. loa microfilariae per millilitre [mf/mL] of blood) increased with an increase in prevalence, varying from 0 mf/mL in the grassland savannah, 325 mf/mL in the deciduous equatorial rainforest, 433 mf/mL in the dense-humid equatorial rainforest, to 3125 mf/mL in the forested savannah. The proportion of individuals with high (> 8000 mf/mL) and very high (> 30,000 mf/mL) L. loa microfilaraemia was greater in bioecological zones with a higher prevalence of L. loa. These results will be valuable for the prediction of loiasis endemicity in different ecological zones of Central Africa and for the refinement of the existing geographical model for the mapping of loiasis.

Adolescent↗

The Wuchereria bancrofti orthologue of Brugia malayi SXP1 and the diagnosis of bancroftian filariasis.

The gene encoding the Wuchereria bancrofti orthologue of the Brugia malayi-derived diagnostic antigen SXP1 was identified from a W. bancrofti L3 cDNA library and characterized. The Wb-sxp-1 cDNA encoded a basic protein with a calculated molecular mass of 20.8 kDa. Wb-SXP-1 was 85% identical to the SXP1 protein described from B. malayi (Bm-SXP-1). The Wb-SXP-1 sequence also showed significant identity with proteins described from B. pahangi, Onchocerca volvulus, Acanthochilonema vitea, Ascaris suum, Loa loa, Litomosoides sigmodontis and Caenorhabditis elegans. The presence of a number of invariant and conserved residues in all of these nematode-derived molecules suggests that Wb-SXP-1 is a member of a new protein family. A recombinant form of Wb-SXP-1 was produced and it was determined that the anti-Wb-SXP-1 antibody response in patients with W. bancrofti infections was restricted to the IgG4 subclass. An anti-Wb-SXP-1 IgG4 ELISA was developed and this assay was found to be 100% sensitive for patients with patent W. bancrofti infection. Sera from individuals experiencing chronic pathology, endemic normals or patients with non-filarial nematode infections had no detectable IgG4 against Wb-SXP-1. While patients with patent Onchocerca volvulus infections were uniformly negative in the Wb-SXP-1 assay, 40% of sera from patent Loa loa infections were positive. When Bm-SXP-1 was used as the antigen under identical conditions, the assay was 88% specific for patent W. bancrofti infections and the antigen was recognized by antibodies from both O. volvulus and L. loa infections. The results strongly suggested that, for certain diagnostic filarial antigens, the use of same-species molecules can enhance the specificity of diagnostic tests.

Amino Acid Sequence↗

Anthropometry-based equations overestimate the urea distribution volume in hemodialysis patients.

BACKGROUND: Protein intake in hemodialysis patients can be estimated indirectly from the protein equivalent of total nitrogen appearance (PNA) during the interdialytic period. A reliable estimate of the patient's urea distribution volume (UDV) is required to assess protein intake from PNA values. UDV values are derived frequently from simple anthropometric equations. METHODS: UDV values based on anthropometric methods were compared with UDV values determined by direct dialysate quantitation (DDQ) in 54 stable chronic hemodialysis patients. The anthropometric methods included the following: the Watson equations (WAT), a fixed proportion of postdialysis body weight, 58% for males and 55% for females (% body wt), and skinfold thickness measurements (SFT). Postdialysis blood samples were drawn at 15-minutes postdialysis. RESULTS: UDV(WAT) and UDV(SFT) overestimated UDV(DDQ) by about 8 L [limits of agreement (LOA): 2.6 to 14.2 L] in males and about 6 L (LOA: -0.8 to 12.4 L) in females. The overestimation by UDV(%BW) was even larger: 10.5 L (LOA: 2.0 to 19.0 L) in males and 11.1 L (LOA: 2.1 to 20.1 L) in females. The difference between UDV(%BW) and UDV(DDQ) correlated with the percentage of body fat (r = 0.57) and body mass index (r = 0.48). In a subgroup of seven patients, UDV was also determined by dilution (DIL) of the stable isotope [(13)C]urea. UDV(WAT) and UDV(%BW) overestimated UDV(DIL) significantly. In contrast, UDV(DDQ) was significantly smaller than UDV(DIL), even after correction for incomplete postdialysis equilibration. PNA values calculated using the various UDV estimates were compared with dietary protein intake (DPI) assessed from food records. PNA(DDQ) (61 +/- 10 g/day) did not differ significantly from DPI (63 +/- 13 g/day), but the agreement in individual patients varied considerably (LOA, -24 to 20 g/day). Anthropometric-based PNA values overestimated DPI by 8 to 16 g/day. CONCLUSIONS: Anthropometry-based equations overestimate UDV values in hemodialysis patients, leading to an overestimation of PNA values. Although PNA measurements by DDQ appear to be more reliable for assessing protein intake, PNA(DDQ) values should be interpreted with caution in individual hemodialysis patients.

Adult↗

Agreement between a brief food frequency questionnaire and diet records using two statistical methods.

OBJECTIVE: To compare intra- and inter-method reliability of a semi-quantitative food frequency questionnaire (FFQ) designed specifically to measure beta carotene (BC) and retinol intake, using two methods - the limits of agreement (LOA) and the correlation coefficient. DESIGN: A cross-sectional study of dietary intake. SETTING: A randomized trial of vitamin A supplements in 2769 subjects with past asbestos exposure. SUBJECTS: Data from 57 men and 26 women, aged 28-72 years, living in Western Australia. METHODS: The FFQ was administered at baseline (FFQ1) and repeated 1 year later (FFQ2). Four 1-week diet records (DRs) were completed during the year. RESULTS: Mean agreement between FFQ2 and FFQ1 was 120% for BC and 98% for retinol. LOA were 47-306% and 21-459%, respectively. Mean agreement between FFQ2 and the DR was 149% for BC and 63% for retinol; LOA were 50-447% and 11-349%, respectively. Mean agreement and LOA varied across energy intakes. Between the DR and FFQ2, correlation coefficients were 0.36 for BC and 0.51 for retinol. These varied considerably across age, gender and energy intakes and were not in accordance with limits of agreement findings. CONCLUSION: Although correlation coefficients were positive and significant, there was less than ideal intra-method and inter-method reliability shown by the limits of agreement method. Bias was uneven across the range of intakes, the LOA were wide and, compared with the DR, the FFQ significantly over-estimated BC and under-estimated retinol. This shows the limitations of calculating correlation coefficients alone, for assessing reliability and validity.

Adult↗

Platelet serotonin uptake is higher in early-onset than in late-onset alcoholics.

The main objective of this study was to compare platelet serotonin (5-HT) uptake between early-onset alcoholics (EOA) and late-onset alcoholics (LOA). Subjects were 24 dependent male alcoholic in-patients and 21 healthy control subjects. 5-HT uptake was quantified by incubating platelets with [3H]5-HT at various concentrations (0.5 to 1000 nM). 5-HT uptake was higher in EOA, compared to both the LOA and control groups (P < 0.02) at the highest 5-HT concentration (1000 nM). No significant difference was found between LOA and controls or between EOA + LOA and controls. Previous studies have shown that 5-HT uptake was higher in platelets, lymphocytes, and brain of alcoholics vs controls, but our data suggest that higher platelet serotonin transporter function is limited to EOA, not LOA.

Adult↗