Traders' views on sale of cigarettes to children.
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Attitude to Health↗
Biomedical subjects
D W Jones
Publications and source records attributed to D W Jones.
Analysis of the metabolites of [I-123] beta-CIT in plasma of human and nonhuman primates.
[I-123] beta-CIT is a single photon emission computed tomography (SPECT) radioligand that has been used for in vivo studies of the dopamine and serotonin transporters. Two metabolite peaks of beta-CIT have been observed by high performance liquid chromatography (HPLC), but neither has been chemically identified. One major metabolite is clearly hydrophilic. Previous reports have not agreed on the amount of the second metabolite and the extent to which it may cross the blood-brain barrier. To clarify this controversy, we have studied beta-CIT metabolites using a protein precipitation method and an organic extraction method followed by HPLC separation. Plasma from both human and nonhuman (rhesus) primates was analyzed. Concentrations of the second metabolite were substantially lower in rhesus than in human for nearly equal parent concentrations. Furthermore, in rhesus the second metabolite is partially soluble in the organic solvent ethyl acetate, whereas in human it is essentially insoluble. These observations account for the contradictions in the literature. The hydrophilic nature of the human metabolite renders it unlikely that it crosses the blood-brain barrier in sufficient quantities to interfere with the quantitative assessment of dopamine transporter densities.
Animals↗
Efficacy of nonpharmacologic interventions in adults with high-normal blood pressure: results from phase 1 of the Trials of Hypertension Prevention. Trials of Hypertension Prevention Collaborative Research Group.
Phase 1 of the Trials of Hypertension Prevention was conducted in 2182 adults, aged 35-54 y, with diastolic blood pressure of 80-89 mm Hg to test the feasibility and blood pressure-lowering effects of seven nonpharmacologic interventions (weight loss, sodium reduction, stress management, and supplementation with calcium, magnesium, potassium, and fish oil). At 6 and 18 mo, weight loss and sodium reduction were well-tolerated and produced significant declines in systolic and diastolic blood pressures (-2.9/-2.4 and -2.1/-1.2 mm Hg for weight loss and sodium reduction, respectively, at 18 mo). None of the other interventions lowered blood pressure significantly at either the 6- or 18-mo follow-up visits. These results suggest that both weight loss and sodium reduction provide an effective means to prevent hypertension. The long-term effects of both of these interventions are being tested in phase 2 of the trial.
Adult↗
Genetic variability of human brain size and cortical gyral patterns.
The development of the primate brain is determined by an interaction of genetic programmes and environmental events. We examined quantitatively the contribution of each of these factors to adult human brain hemisphere volume and global cortical gyral patterns by comparing 3-D MRI renderings of brains of 10 pairs of monozygotic (MZ) and nine pairs of same-sex dizygotic (DZ) twins. Brain volume was highly correlated in MZ pairs [unbiased intraclass correlation coefficient, ICC(U) = 0.95, P < 0.00001], but not in DZ pairs [ICC(U) = 0.35, P = 0.09]. Structural equation modelling indicated a 94% heritability of brain volume. Gyral patterns appeared visually more similar in MZ than in DZ pairs. This was confirmed statistically by a cross-correlation analysis of rendered images of lateral and mesial cortical surfaces. MZ twins exhibited significantly greater similarity than did DZ twins in comparisons of gyral patterns; DZ twins were not more alike than unrelated pairings. Ipsilateral hemispheres were significantly more alike than contralateral hemispheres within MZ pairs, but not within DZ pairs. Contralateral hemispheres within an individual were more alike than contralateral hemispheres between twins in the DZ pairs, but not in the MZ pairs. Heritability for gyral-sulcal patterns, as reflected in the cross-correlation data, was low and ill defined. These results indicate that human cerebral size is determined almost entirely by genetic factors and that overall cortical gyral patterns, though significantly affected by genes, are determined primarily by nongenetic factors.
Adolescent↗
Factor XII determinations and lupus anticoagulants.
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Factor XII↗
Joint position sense and rehabilitation in the anterior cruciate ligament deficient knee.
BACKGROUND: Impaired joint position sense (JPS) has been shown in anterior cruciate ligament (ACL) deficient and osteoarthritic knees. The relation between JPS and function is uncertain. The aim of this study was to determine further if ACL deficient knees show abnormal JPS and the effect of exercise therapy on JPS, and also to assess the relation between JPS, functional stability, and strength. METHODS: Fifty patients (46 men and four women, mean age 26.3 years) with unilateral ACL deficient knees were assessed on admission and after rehabilitation (5 hours a day for four weeks). JPS was assessed by reproduction of passive positioning using a visual analogue incorporating a goniometer. Knee stability was analysed by self report questionnaire (score 0-280) and functional activity test (single leg hop and figure of eight run). Isokinetic dynamometry was performed to evaluate quadriceps and hamstring peak torque strength. Controls were either age and sex matched individuals or the contralateral knee. Statistical analysis was by Wilcoxon signed rank test and Spearman rank order correlation coefficient. RESULTS: JPS was impaired in ACL deficient knees. The mean (SD) errors in reproducing angles were 9.4 (3.1) degrees and 7.1 (2.3) degrees for the ACL deficient knee and control knee respectively (P < 0.0005). There was no improvement in JPS after rehabilitation (9.4 (3.1) degrees and 8.5 (3.2) degrees before and after rehabilitation respectively, P = 0.14). There was improvement as ascertained from the questionnaire (on admission 202 (32.1), after rehabilitation 243 (25.4), P < 0.0001) and functional activity testing (hop: on admission 148.7 (37.3) cm, after rehabilitation 169.8 (31.1) cm, P < 0.0005; figure of eight: on admission 48.4 (16.6) seconds, after rehabilitation 41.6 (3.4) seconds, P < 0.0001). Quadriceps strength improved (peak torque on admission 198.5 (58.9) Nm, after rehabilitation 210.5 (54.2) Nm, P < 0.05), but not hamstring strength (peak torque on admission 130.6 (28.1) Nm, after rehabilitation 135.5 (27.7) Nm, P = 0.24). JPS did not correlate with the functional activity tests (hop and figure of eight run), the responses to the questionnaire, or strength. There was no correlation between the responses to the questionnaire and functional activity tests or muscle strength. CONCLUSIONS: JPS was impaired in ACL deficient knees. Although knee stability improved with exercise therapy, there was no improvement in JPS. The role of JPS in the stability of ACL deficient knees remains unclear.
Adult↗
Variations in circadian rhythms of activity, sleep, and light exposure related to dementia in nursing-home patients.
We measured 24-hour circadian-rhythm patterns of activity and sleep/wake activity in a group of nursing-home patients (58 women and 19 men with a mean age of 85.7 years). Severely demented patients were contrasted with a composite group of moderate y, mild, or not-demented patients. Sleep/wake activity and light exposure were recorded with the Actillume recorder. Cosinor analyses were computed to determine the mesor, amplitude, acrophase, and circadian quotient of the activity rhythms. The diagnosis of dementia was based on the Mini Mental Examination and on examination of medical records. Sleep was extremely fragmented in both groups of nursing-home patients. Severely demented patients slept more both at night and during the day, but there were no significant differences in the number of awakenings during the night or in the number of naps during the day when compared to the composite group of moderate, mild, or no-dementia patients. The severely demented group had lower activity mesor, more blunted amplitude, and were more phase delayed (i.e. had later acrophases) than the other group. In addition, the severely demented patients spent less time exposed to bright light. These results confirm that circadian rhythms in nursing-home patients are disturbed with more disturbance in the severely demented. Much of the disturbance may be related not just to age but to mental status.
Aged↗
Cortical gyral anatomy and gross brain dimensions in monozygotic twins discordant for schizophrenia.
BACKGROUND: This study combines recent advances in three-dimensional neuroimaging technology and the genetic constraints inherent in monozygotic (MZ) twins to examine surface gyral anatomy and gross brain dimensions in monozygotic twin pairs discordant for schizophrenia. Results are presented and evaluated with respect to prior observations of cortical anomalies in schizophrenia and the hypothesis that schizophrenia involves cortical maldevelopment. DESIGN: Three-dimensional renderings from volumetric magnetic resonance imaging (MRI) data of 13 MZ twin pairs discordant for schizophrenia and nine normal MZ pairs were studied. Qualitative assessments of left and right hemisphere surfaces were made by raters blind to diagnosis in an effect to identify developmental gyral abnormalities such as vertical temporal gyri or microgyria. Measurement of brain hemisphere length, area, and volume were also determined. These data were compared within discordant MZ schizophrenia pairs, within normal MZ pairs, and between matched unaffected discordant and normal MZ groups. RESULTS: Raters did not identify qualitatively abnormal gyri in the schizophrenia subjects to enable distinction from their unaffected co-twins or from normal controls. Brain hemisphere volumes in the affected DS were significantly smaller bilaterally by about 3% compared with their unaffected DS co-twins, who did not differ from normals on this measure. CONCLUSIONS: We were unable to confirm previous reports of vertical gyri or localized gyral thinning as being characteristic of the cortical anatomy of schizophrenia. If cortical maldevelopment is associated with schizophrenia it does not appear to disrupt gross gyral pattern formation in these ways. The quantitative results of diminished hemisphere volume and length in the twins with schizophrenia are consistent with previous reports of smaller brain size in schizophrenia. Our results suggest that this is a bilateral phenomenon that may be dependent, at least in part, on environmental factors.
Adult↗
Tourette syndrome: prediction of phenotypic variation in monozygotic twins by caudate nucleus D2 receptor binding.
Tourette syndrome, a chronic tic disorder with autosomal dominant inheritance, exhibits considerable phenotypic variability even within monozygotic twin pairs. The origins of this variability remain unclear. Recent findings have implicated the caudate nucleus as a locus of pathology, and pharmacological evidence supports dopaminergic involvement. Within monozygotic twins discordant for Tourette syndrome severity, differences in D2 dopamine receptor binding in the head of the caudate nucleus predicted differences in phenotypic severity (r = 0.99); this relation was not observed in putamen. These data may link Tourette syndrome with a spectrum of neuropsychiatric disorders that involve associative striatal circuitry.
Adult↗
Crystallization of experimental bioactive glass compositions.
Crystallization kinetics studies for six experimental glass formulations in the system Na2O-CaO-SiO2-P2O5 synthesized by wet chemistry were conducted by means of differential thermal analysis. These glasses had CaO/P2O5 and SiO2/ (CaO + Na2O) ratios ranging from 8.74-3.38 and 0.92-3.03, respectively. Samples of each glass (n = 30 were heated from 23 to 1250 degrees C under N2 atmosphere at heating rates ranging from 10 to 50 degrees C/min. Glass-ceramics were obtained after heat treating the initial glasses at temperatures determined from their DTA exotherms. The activation energy of crystallization for each glass composition was calculated from an expression-relating log-heating rate and the reciprocal of the exothermic peak temperature. The compositions of the six glasses were significantly different (p = 0.05). The activation energy of crystallization (Q) values ranged from 196 to 782 kJ/mole. A correlation was obtained between Q and CaO/P2O5 and between Q and the Young's modulus (P < 0.001). Two of the six glasses exhibited bulk crystallization. X-ray diffraction studies showed that four of the six glasses exhibited different proportions of crystalline phases following heat treatment. These phases were wollastonite (CaSiO3), Na2CaSi3O9, combeite [Na4Ca3SI6O16(OH)2], and some unidentifiable phases. Two of the six bioceramic materials had a mixture of unknown crystalline phases.
Biocompatible Materials↗
Characterization of experimental composite biomaterials.
A comparison was made among the elastic moduli of various combinations of dimethacrylates that may be used as matrix resins in dental restorative composite biomaterials systems. Two ceramic filler materials with contrasting shape and size were synthesized by wet chemistry; these were used to produce a range of experimental composite systems. Dynamic elastic moduli determinations were used to study the influence of filler volume, filler size/shape, use of silane coupling agents, and storage in water. The filler was varied from 0 to 59% by volume for filler A and from 0 to 48% volume for filler B. Silane treatment was found to have a significant effect on modulus. Moduli for composite materials containing silane-treated filler were higher compared to materials containing the same volume loading of non-silane-treated filler. Using a light curing resin as a matrix gave a significantly higher modulus for a filler loading of 38% by volume. Storage in water for 29 days was found to have only a slight effect on moduli for composite systems containing in excess of 20% by volume of filler. The experimental composite systems produced slightly higher values for moduli than were predicted by the theoretical Reuse constant stress model.
Adsorption↗
Body weight and blood pressure. Effects of weight reduction on hypertension.
A substudy of the Hypertension Optimal Treatment study, conducted in the Jackson Mississippi Center, set out to determine the link between obesity and hypertension and to determine the effects of weight loss in hypertensive individuals. An analysis of the relationship between body mass index and diastolic blood pressure for another study showed that increasing body mass indices were associated with increases in blood pressure. This indicates that not only is there a strong relationship between obesity and hypertension, but that there is also a close association between the continuous variables of body mass index and blood pressure. The purpose of the present study was to determine the effectiveness of a weight loss regimen in reducing the amount of medication required to achieve the target blood pressure in 228 patients at the Jackson center. Subjects were randomized to a dietary intervention group or to a control group. Preliminary 3 month observational data showed that subjects who lost the appropriate amount of weight were three times more likely to achieve their target blood pressure at 3 months. These observations suggest that weight reduction regimens can reduce elevated blood pressure and can probably promote further blood pressure reductions when combined with drug therapy in the treatment of hypertension.
Blood Pressure↗
Cardiovascular effects of cocaine in neonates exposed prenatally.
This blinded cross-sectional study was to determine whether chronic cocaine exposure in utero produces abnormalities in left ventricular function (shortening fraction), heart rate, rhythm, and conduction in term neonates. Three groups of neonates were evaluated by two-dimensional echo Doppler and 24 hour Holter monitor, with studies initiated in the first 24 hours of life. Group A (n = 32) neonates had a positive history of chronic maternal cocaine use in pregnancy (MCU+) and a positive neonatal urine cocaine test (NUC+). Group B (n = 23) neonates were MCU+ but NUC-. Group C (n = 32) neonates were MCU- and NUC-. Measured parameters were compared statistically by analysis of variance. p < 0.05 was regarded as significant. Echocardiography showed no significant difference between groups A, B, and C for left ventricular shortening fraction. Holter monitor likewise revealed no significant difference between groups in minimal, maximal, and average heart rate, or in the incidence of supraventricular and ventricular arrhythmias greater than 20 beats/h in the 24-hour period. None of the patients had atrioventricular or bundle branch block. It is possible that the developmental state of the newborn heart makes it less responsive to the adverse effects of cocaine.
Analysis of Variance↗
Hypertension awareness, treatment and control rates for an Asian population: results from a national survey in Korea.
OBJECTIVE: This observational study was performed in order to determine the hypertension awareness, treatment, and control rates for the country of Korea. METHODS: Rates were determined in conjunction with a national blood pressure survey in Korea in 1990. Through cluster sampling, individuals aged > 30 in 190/146,944 districts were selected for study. Among 25,567 eligible individuals, 21,242 had measurement of blood pressure (BP) and answered a standard questionnaire. BP was recorded as the mean of two measurements with a standard mercury manometer. Hypertension was defined either as BP > or = 160/95 mm Hg or on treatment (n = 2628), or as BP > or = 140/90 mm Hg or on treatment (n = 4219). Treatment was defined as any method of BP treatment, including dietary, traditional, or medication. RESULTS: Rates for BP > or = 160/95 mm Hg or on treatment: aware 1057 (40%), treated 696 (27%), controlled 367 (14%). Rates for BP > or = 140/90 mm Hg or on treatment: aware 1069 (25%), treated 696 (16%), controlled 221 (5%). CONCLUSIONS: Hypertension awareness, treatment, and control rates are relatively low in Korea. Blood-pressure control programs, including detection strategies, are needed here and worldwide.
Adult↗
Superior temporal gyrus volume in schizophrenia: a study using MRI morphometry assisted by surface rendering.
OBJECTIVE: Interpretation of the literature concerning superior temporal gyrus volume in patients with schizophrenia is complicated by methodological variation between studies and by the difficulty of identifying gyral boundaries in serial sections. METHOD: With the aid of three-dimensional cortical renderings, the authors developed a morphometric approach in which information from the cortical surface is incorporated into gyral boundary decisions. Using this technique, they assessed superior temporal gyrus volume in young, right-handed male patients with schizophrenia and in right-handed male comparison subjects. They also compared their technique with existing slice-based morphometric methods by using previously reported subcortical landmarks to define the gyral boundaries. RESULTS: There was no significant main effect of diagnosis and no significant diagnosis-by-hemisphere interaction. Significant leftward laterality was present only among comparison subjects. Leftward superior temporal gyrus laterality did not correlate with leftward laterality of the planum temporale. No significant reduction in superior temporal gyrus volume was revealed in the patients. No significant leftward laterality was detected with the slice-based technique, suggesting that a significant portion of superior temporal gyrus tissue is omitted with this approach. The lack of findings could not be explained by a general absence of morphometric abnormalities in this group of subjects because the patients had significantly larger lateral ventricles. CONCLUSIONS: Significant reduction in the superior temporal gyrus volume was not confirmed in this group of patients with schizophrenia, probably because of the small effect size of this finding. Methodological variation is an important factor in determining superior temporal gyrus volume on magnetic resonance imaging scans.
Adult↗
Effect of ranitidine on theophylline metabolism in healthy Koreans living in China.
OBJECTIVE: To evaluate the effect of concurrent ranitidine therapy on theophylline metabolism in healthy Koreans. DESIGN: A 4-week, double-blind, randomized, placebo-controlled, crossover study. SETTING: The Clinical Research Unit, Department of Pharmaceutical Sciences, Yanbian Medical College, Yanji, China. SUBJECTS: Six young, healthy, nonsmoking Korean volunteers residing in China with no known factors that would alter theophylline metabolism. INTERVENTIONS: Subjects received extended-release oral theophylline at a constant dosage over 4 weeks to yield a serum concentration (Cp) between 5 and 10 micrograms/mL. Week 1 was the dosage titration phase. During week 2 subjects randomly received either ranitidine or a matching placebo. Week 3 was a washout phase, and during week 4 subjects were crossed over to receive either placebo or ranitidine. At the end of each treatment week, serum and urinary metabolite concentrations were measured. OUTCOME MEASURES: Theophylline serum concentrations and urinary concentrations of 1-methylxanthine, 1-methyluric acid, 3-methylxanthine, and 1,3-dimethyluric acid were measured. Estimates of clearance (Cl), volume of distribution (Vd), and half-life (t1/2) were determined. RESULTS: Concurrent administration of ranitidine with theophylline did not significantly alter theophylline Cp, Cl, Vd, or t1/2. Urinary concentrations of major theophylline metabolites also were not changed. CONCLUSIONS: Ranitidine does not significantly alter the metabolism of theophylline in healthy Koreans residing in China.
Adolescent↗
Pseudo factor XII deficiency and phospholipid antibodies.
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Antibodies, Antiphospholipid↗
Computerized Wisconsin Card Sorting Test: comparison with manual administration.
Computer-based testing in neuropsychology potentially offers important advantages. These include improvement in reliability and more efficient use of resources. For tests such as the Wisconsin Card Sorting Test (WCST) in which examiners must provide on-going feedback to subjects, reliability may be decreased by variability and errors in test presentation, errors in response recording and feedback, and errors in scoring. In addition, an important aspects of neuropsychological assessment is qualitative, that is, observations of the processes by which the subject responds to the test situation. The mechanics of administering the WCST hinder the examiner from allocating attention for observing these processes. Accordingly, we have automated both the administration and the scoring of the WCST. Although potential benefits of computerizing the WCST seem likely, it is possible that factors which cannot at present be duplicated by a computer may effect performance. This study compared performance between the standard manual Heaton version of the WCST and the computerized version. In a group of 33 normal and psychiatric subjects, there were significant differences in the number of Errors and the number of Correct responses, but no significant differences in performance were found for Perseverative Responses, Perseverative Errors, and Set Breaks. The mean number of Categories achieved was 2.0 for the computer administered version and 2.4 for the manual version: this difference was only marginally significant (p = 0.065). The computerized form of the WCST appears to yield similar quantitative results on scores which are most specifically affected by brain injuries in testing with the manual form. Lower variance was seen in the computer scores. This result is consistent with more reliable administration and accuracy in data acquisition and scoring in the computer version. The results overall indicate that the computer version is not a substitute for a human examiner, rather, the computer can function as a reliable partner, carrying out the mechanics of test presentation and scoring, freeing the examiner to more fully support the subject in taking the test and to observe the non-quantitative aspects of test performance.
Adolescent↗