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PubMed2005

Beliefs of Turkish and Moroccan immigrants in The Netherlands about smoking cessation: implications for prevention.

Tobacco smoking is a very important preventable cause of mortality and morbidity, and this is also the case in immigrant populations. Therefore, smoking cessation interventions need to take these groups into account. Insight into the applicability of behavioral smoking cessation interventions for non-Western populations is necessary. The objective of our study is to gain insight into the beliefs of smoking cessation in Turkish and Moroccan immigrants in The Netherlands using the I-Change Model. In this model, intention and behavior are supposed to be determined by three types of (psychosocial) factors: attitudes, social influences and self-efficacy expectations. Face-to-face structured interviews among Turkish and Moroccan immigrants were conducted. Results indicate that in contrast to smokers, ex-smokers perceived fewer advantages of smoking and more advantages of smoking cessation. They also perceived less social pressure that encourages smoking (e.g. by being offered cigarettes) and a high self-efficacy of being able to quit. The I-Change Model explained 66% of the observed variance. We conclude that the basic factors identified in social cognition theories were replicated in this study. When developing smoking cessation interventions, the results show that it is important to include ethnic-specific salient beliefs, such as the subjective norms of the religious leader.

Adult↗

PubMed1997

A novel mechanism generating short deletion/insertions following slippage is suggested by a mutation in the human alpha2-globin gene.

A novel mechanism generating short deletion/insertions is described based on a mutation in the human alpha2-globin gene. A deletion of 9 bp (codons 39-41) is replaced by an eight nucleotide insertion, duplicating the adjacent downstream sequence. We propose that the mutation arose by slipped strand mispairing (SSM), creating a single-stranded loop, followed by DNA elongation, strand breathing and the formation of a mismatch bubble. An extensive literature search has revealed six additional deletion/insertion mutations in humans in which the inserted nucleotides come from the same DNA strand. Our model explains all six mutations, suggesting that rearrangement of a mismatch loop or bubble during DNA replication may be not uncommon.

Adolescent↗

PubMedDate not supplied

Tandem repeat polymorphism and heteroplasmy in the mitochondrial control region of redfishes (Sebastes: Scorpaenidae).

Three species of redfish (Sebastes) share a common pattern of mitochondrial DNA tandem repeat polymorphism and heteroplasmy in the northwest Atlantic Ocean. All three species exhibit 9-17 copies of an approximately 275 base pair (bp) tandem repeat situated within the 3' domain of the control region. Sequence analysis of cloned mtDNA from S. mentella revealed that the tandem array is adjacent to the tRNA(phe) gene, and that the repeat shares 53% identity with the tRNA(phe) gene and part of the 12S rRNA gene. These features, as well as potential secondary structure assumed by the repeat, are consistent with previously proposed models explaining tandem duplications in the 3' end of the control region. In a sample comprising 36 S. fasciatus, 52 S. mentella, and 13 S. marinus taken near Newfoundland, neither the mean number of repeats per fish (12.2-12.7) nor the frequency of heteroplasmy varied significantly among species. A total of 42% of the redfishes were heteroplasmic, bearing either two or three repeat variants (33% and 9%, respectively). The similarity of the frequency distributions of tandem repeat variants in the three species suggests either a common balance between mutation and selection in the three species, or mitochondrial gene flow between them.

Animals↗

PubMed2001

Serum concentrations of retinol, alpha-tocopherol and the carotenoids are influenced by diet, race and obesity in a sample of healthy adolescents.

An important part of understanding the functions of vitamin A, vitamin E and the carotenoids in nutritional status assessment, health promotion and disease prevention is knowledge of factors that influence their distribution in human tissues. Our objective was to examine serum concentrations of these nutrients and compounds in a sample of 285 healthy participants, 12-17 y old, from three U. S. cities. Pearson correlations between diet measured with a food frequency questionnaire and serum nutrient concentrations among these adolescents (adjusted for total serum cholesterol, age, sex, race and body mass index) were as follows: retinol, 0.23; alpha-tocopherol, 0.16; alpha-carotene, 0.31; beta-carotene, 0.15; beta-cryptoxanthin, 0.38; lycopene, 0.08; and lutein + zeaxanthin, 0.25. Multivariate linear regression modeled associations of demographic, dietary and physiologic variables with serum concentrations of these nutrients. African-American participants had significantly lower concentrations of serum retinol (P < 0.001), alpha-tocopherol (P < 0.01) and alpha-carotene (P < 0.02), but higher concentrations of lutein + zeaxanthin (P = 0.001) compared with Caucasians. Obese participants had serum nutrient concentrations that were 2-10% (P < 0.05) lower than normal weight participants. Dietary intake was a significant predictor of all serum analytes (P < 0.01) except lycopene. These models explained 20% of the variability in serum retinol, 28% of the variability in serum alpha-tocopherol, and 14-24% of the variability in serum carotenoids.

Adolescent↗

PubMed2002

Nutritional status and linear growth of Indonesian infants in west java are determined more by prenatal environment than by postnatal factors.

One of the health problems in Indonesia is the high prevalence of stunting in infants. Determinants and specifically the relative contribution of prenatal and postnatal factors to growth and nutritional status of Indonesian infants were investigated. Newborn infants, from women recruited at approximately 18 wk of pregnancy from 9 rural villages in West Java, Indonesia, were followed until 12-15 mo of age. Weight, length, morbidity, breast-feeding and food intake were assessed monthly. Determinants of length and weight increase and nutritional status reflected by Z-scores were evaluated using multiple linear regression. Neonatal weight (3.2 +/- 0.5 kg) and length (49.7 +/- 2.2 cm) were reasonable. However, growth started to falter at 6-7 mo of age, resulting in prevalences of 24% stunting and 32% underweight at 12 mo of age. The multiple regression models explained 19-41% of the variation in growth and nutritional status of infants. Neonatal weight (beta = 0.285) and length (beta = 0.492) were the strongest positive predictors of weight-for-age and height-for-age Z-scores, respectively. Fever was negatively associated with weight increase (beta = -0.144) and weight-for-age (beta = -0.142) and weight-for-height Z-scores (beta = -0.255) but not with length increase or height-for-age Z-scores. Intake of complementary foods was positively associated with increases in weight (beta = 0.190) and length (beta = 0.179) and nutritional status of infants (beta = 0.136-0.194). In conclusion, in this rural population in West Java, neonatal weight and especially length, reflecting the prenatal environment, are the most important predictors of infant nutritional status.

Adult↗

PubMed1992

Psychosocial adjustment in juvenile arthritis.

Psychosocial adjustment in 102 children with arthritis, ages 4-16, and their families was assessed by parents, who completed the Child Behavior Checklist (CBCL) and Profile of Mood States (POMS). On average, parental distress (POMS) was lower than reference norms. POMS distress was correlated with children's behavioral problems (r = .41) but not with children's social competence (r = .15). General linear models explained 25% of the variance in CBCL behavioral problem scores. Older age was associated with more behavior problems in males, but not females. Disease severity and disease activity were also associated with behavioral problems. Although 27% of the variance in CBCL social competence could be explained, no single predictor variable was especially strong. Poorer social competence was associated with older age and shorter disease duration. Teenagers, especially those with recent onset and those with mild disease activity, may be at increased risk for psychosocial maladjustment.

Adaptation, Psychological↗

PubMed1993

Interlocked circle formation by group I introns: structural requirements and mechanism.

Precursor RNA transcribed from the yeast mitochondrial gene coding for the large ribosomal RNA contains a group I intron that can excise itself in vitro. Apart from group I specific sequence elements the intron also contains a gene encoding a DNA endonuclease involved in intron dispersal. A precursor RNA derivative from which this gene has been removed self-splices efficiently, but due to activation of cryptic opening sites located in the 5' exon, the 3' part of this exon is sometimes co-excised with the intron. Upon further reaction, this enlarged intron molecules give rise to interlocked circles, comprising small circles derived from 5' exon parts and large circles of the intron. Sequence comparison between cryptic opening sites and authentic splice sites reveals in most cases homology with the 3' exon part that is capable of interacting with the Internal Guide Sequence. The role of the IGS was further substantiated by replacing the cryptic opening sites with well defined sequences of authentic splice sites: one corresponding to the 3' splice site and its mutant derivatives, the other to a fragment containing the natural 5'-3' exon junction. Precursor RNAs derived from these constructs give rise to interlocked circles, and mutation studies confirm that the 3' exon nucleotides flanking a 3' splice site are essential for their formation. The results underline the crucial role of the IGS in interlocked circle formation which behaves similarly as in the normal self-splicing reactions. It has been proposed that the two short helices formed by basepairing of the IGS with the 5' and 3' exon can co-axially stack on top of each other forming a quasi continuous RNA double helix or pseudoknot. We present a model explaining how transesterification reactions of a mutant precursor RNA in such a pseudoknot can lead to interlocked circles. The experiments support the notion that a similar structure is also operative in splicing of wild type precursor RNA.

Base Sequence↗

PubMed1996

Processing of branched DNA intermediates by a complex of human FEN-1 and PCNA.

In eukaryotic cells, a 5' flap DNA endonuclease activity and a ds DNA 5'-exonuclease activity exist within a single enzyme called FEN-1 [flap endo-nuclease and 5(five)'-exo-nuclease]. This 42 kDa endo-/exonuclease, FEN-1, is highly homologous to human XP-G, Saccharomyces cerevisiae RAD2 and S.cerevisiae RTH1. These structure-specific nucleases recognize and cleave a branched DNA structure called a DNA flap, and its derivative called a pseudo Y-structure. FEN-1 is essential for lagging strand DNA synthesis in Okazaki fragment joining. FEN-1 also appears to be important in mismatch repair. Here we find that human PCNA, the processivity factor for eukaryotic polymerases, physically associates with human FEN-1 and stimulates its endonucleolytic activity at branched DNA structures and its exonucleolytic activity at nick and gap structures. Structural requirements for FEN-1 and PCNA loading provide an interesting picture of this stimulation. PCNA loads on to substrates at double-stranded DNA ends. In contrast, FEN-1 requires a free single-stranded 5' terminus and appears to load by tracking along the single-stranded DNA branch. These physical constraints define the range of DNA replication, recombination and repair processes in which this family of structure-specific nucleases participate. A model explaining the exonucleolytic activity of FEN-1 in terms of its endonucleolytic activity is proposed based on these observations.

Antibodies, Monoclonal↗

PubMed2005

HIV-1 integrase crosslinked oligomers are active in vitro.

The oligomeric state of active human immunodeficiency virus type 1 (HIV-1) integrase (IN) has not been clearly elucidated. We analyzed the activity of the different purified oligomeric forms of recombinant IN obtained after stabilization by platinum crosslinking. The crosslinked tetramer isolated by gel chromatography was able to catalyze the full-site integration of the two viral LTR ends into a target DNA in vitro, whereas the isolated dimeric form of the enzyme was involved in the processing and integration of only one viral end. Accurate concerted integration by IN tetramers was confirmed by cloning and sequencing. Kinetic studies of DNA-integrase complexes led us to propose a model explaining the formation of an active complex. Our data suggest that the tetrameric IN bound to the viral DNA ends is the minimal complex involved in the concerted integration of both LTRs and should be the oligomeric form targeted by future inhibitors.

Cross-Linking Reagents↗

PubMed2002

Determinants of circulating soluble transferrin receptor level in chronic haemodialysis patients.

BACKGROUND: The aim of this study was to identify the factors determining the circulating soluble transferrin receptor (sTfR) concentrations in haemodialysis (HD) patients on maintenance recombinant human erythropoietin (rHuEpo) treatment. METHODS: In a prospective cross-sectional study, 91 chronic HD patients and 18 anaemic controls with normal renal function were recruited. For each subject, blood samples were measured for complete blood count, reticulocyte count, percentage of hypochromic red cells (% HRC), serum ferritin, serum iron, transferrin saturation (TS), serum erythropoietin (sEpo), C-reactive protein (CRP), and sTfR. HD patients received constant rHuEpo doses and basal sEpo was measured > or = 86 h after the last injection. The age, gender, dialysis vintage, and the above-mentioned parameters were used as independent variables and logarithmic sTfR (log(10)sTfR) as a dependent variable in the forward stepwise multiple regression model. RESULTS: HD patients were similar to controls regarding haematocrit, serum ferritin, TS, and % HRC, but had significantly lower sTfR, sEpo, and reticulocyte index. Univariate analyses showed that the sTfR level strongly correlated with sEpo (r=0.60, P<0.001) and % HRC (r=0.60, P<0.001), and significantly with serum ferritin (r=-0.29, P<0.01), TS (r=-0.27, P<0.05), and dose of rHuEpo administered (r=0.27, P<0.05) in HD patients. sTfR also had a positive correlation with haematocrit (r=0.26, P<0.05), red blood cell (RBC) count (r=0.23, P<0.05), and reticulocyte count (r=0.24, P<0.05), but not with CRP (r=0.16, P>0.05). Multivariate regression analysis disclosed that sEpo, HRC, and serum ferritin were the independent predictors of sTfR level. Overall, the model explained 58.8% of the variability in sTfR (R(2)=0.588, P<0.001). CONCLUSIONS: Circulating sTfR is a good index of marrow erythropoietic activity in HD patients during rHuEpo treatment. Its level is also independently up-regulated by functional iron deficiency in the process of enhanced erythropoiesis. Our study showed that sTfR levels quantitatively reflect the integrated effects of iron availability, iron reserves, and erythropoietic stimulation.

Biomarkers↗

PubMed2003

A simple risk score predicts poor quality of life and non-survival at 1 year follow-up in dialysis patients.

BACKGROUND: Quality of life (QoL) in end-stage renal disease patients has become an important focus of attention in evaluating dialysis. We studied risk factors of poor QoL at 1 year follow-up. METHODS: Of a baseline sample of 80 dialysis patients, we contacted 60 patients who were alive at 1 year follow-up. QoL data were obtained for 46 (76.7%) of these patients. QoL measured with the SF-36 [physical health component score (PCS) and mental health component score (MCS)] at 1 year-follow-up was predicted by means of multivariate regression analysis by data collected at baseline using INTERMED-an observer-rated method to assess biopsychosocial care needs-and several indicators for disease severity and comorbidity. RESULTS: The regression models explained 32% of the variance in PCS and 40% in MCS. INTERMED score (P < 0.01) was the only independent risk factor for low MCS, while for low PCS, diabetic comorbidity (P = 0.02) and age (P = 0.03) were independent risk factors. A simple risk score consisting of INTERMED > or =21, diabetic comorbidity and age > or =65 was significantly correlated with non-survival (P = 0.02) and with PCS (P < 0.01) and MCS (P < 0.01) in surviving patients, although not with hospital admissions during follow-up. CONCLUSIONS: A simple risk score based on INTERMED, age (> or =65) and comorbid diabetes (yes/no) can be used to detect patients at risk of poor QoL and non-survival at an early stage of treatment.

Adolescent↗

PubMed2003

Occupational and social variation in subjective health complaints.

OBJECTIVES: Occupational and social factors are thought to be important determinants of health inequality. The aim of this study was to examine the relationships between occupation, lifestyle and subjective health complaints (SHC). METHODS: SHC and self-reported sickness absence were recorded in a cross-sectional study of 662 individuals aged between 16 and 67 from five occupational groups: blue-collar, school/education, health service, white-collar and service. Differences in SHC and sickness absence were investigated. A model of sociodemographic, lifestyle and work-related factors was tested to examine associations with SHC. RESULTS: Few differences in SHC and sickness absence were found when educational level, age and gender were controlled for. Female health service workers did, however, show significantly higher prevalence of pseudoneurological complaints compared with white-collar workers. Male blue-collar workers had significantly higher frequency of sickness absence than white-collar workers; otherwise, there were no significant differences in frequency and duration of sickness absence. The model explained very little of the variance of SHC (R(2)(adj) = 0.15) and occupational group was not significantly associated with health. Physical workload and sleep quality showed significant relationships with SHC for both genders. Education, however, was a significant factor for women only. CONCLUSIONS: The differences in health found between major occupational groups in this sample were mainly explained by gender differences. Sociodemographic, lifestyle and work-related factors explained little of the variance in SHC, suggesting that factors such as psychological demands, perceived job stress, coping and other psychological factors might be of stronger importance for SHC.

Adolescent↗

PubMed1988

Self-reported expected effects of a moderate dose of alcohol by college women.

Fifty college undergraduate women were asked to state the three most probable effects they expected from drinking a moderate amount of alcohol for themselves and for others respectively in rank-ordered way. Results indicate that subjects expected primarily over-all positive effects both for themselves and for others. Specifically they also expected themselves to become more calm and others to behave generally less well. Lower down in the level of expectations there was a tendency to expect more positive effects for themselves and more negative effects for others. The importance of establishing not only the existence of an expectancy but also the relationship between expectancies in terms of internal dominance is discussed along with a model explaining the interplay between expectancies and social behavior.

Adult↗

PubMed2002

The zero signal and glow curves of bare LiF:Mg,Ti detectors in a hot gas TLD system.

The uncertainty in very low doses measured with TLDs is partly caused by the uncertainty in the zero signal of the detector. A mathematical model for the thermodynamics of TLD heating and the zero signal in a hot gas reader with constant gas temperature is presented. The major component of the heating is described as diffusion limited conductive heating, the major component of the zero signal is black body radiation from the hot TLD. The parameters in the model were determined from the glow curves recorded at five different gas temperatures. The model explains the shape and statistics of a zero signal glow curve and can be used in the quality control of non-irradiated TLDs before calibration irradiation and readout.

Fluorides↗

PubMed2000

Distress attributed to negative symptoms in schizophrenia.

The purpose of the study was to examine (1) to which negative symptoms schizophrenia patients attribute distress and (2) whether clinical variables can predict the levels of reported distress. With the help of a research assistant, 86 hospitalized patients completed a self-rating scale for negative symptoms. The 21 items of the self-rating scale were taken from the Scale for the Assessment of Negative Symptoms (SANS). A psychiatrist rated the patients on a number of scales, including the SANS. When patients reported particular symptoms, they were asked whether those symptoms bothered or distressed them. Answers to this question were highly dependent on the type of symptom involved. Distress was most often attributed to symptoms in the subscale avolition-apathy. Patients were also asked how much they were bothered or distressed. Again, high levels of distress were most often attributed to items in the subscale avolition-apathy. A summary score was developed for the level of reported distress: the distress score. Regression analysis showed that distress scores were not associated with the observed severity of negative symptoms or with the level of psychiatric disability. High distress scores were best predicted by the combination of high scores for depression and high scores for insight into positive symptomatology. However, this model explained only a quarter of the variance in distress scores.

Adult↗

PubMed2006

The female-specific Cs-ACS1G gene of cucumber. A case of gene duplication and recombination between the non-sex-specific 1-aminocyclopropane-1-carboxylate synthase gene and a branched-chain amino acid transaminase gene.

Cucumber (Cucumis sativus L.) is a monoecious plant in which female sex expression (gynoecy) is controlled by the Female (F) locus that can be modified by other sex-determining genes as well as by environmental and hormonal factors. As in many other cucurbits, ethylene is the major plant hormone regulating female sex expression. Previously we isolated the Cs-ACS1 (ACS, 1-aminocyclopropane-1-carboxylate synthase) gene that encodes the rate-limiting enzyme in the ethylene biosynthetic pathway. We proposed that Cs-ACS1 is present in a single copy in monoecious (ffMM) plants whereas gynoecious plants (FFMM) contain an additional copy Cs-ACS1G that was mapped to the F locus. To study the origin of Cs-ACS1G, we cloned and analyzed both the gynoecious-specific Cs-ACS1G gene and the non-sex-specific Cs-ACS1 gene. Our results indicate that Cs-ACS1G is the result of a relatively recent gene duplication and recombination, between Cs-ACS1 and a branched-chain amino acid transaminase (BCAT) gene. Taking into consideration that the Cs-ACS1G gene was mapped to the F locus, we propose that this duplication event gave rise to the F locus and to gynoecious cucumber plants. Computer analysis of the 1 kb region upstream of the transcription initiation site revealed several putative cis-acting regulatory elements that can potentially confer the responsiveness of Cs-ACS1G to developmental and hormonal factors and thereby control female sex determination in cucumber. These findings lead us to a model explaining the action of Cs-ACS1 and Cs-ACS1G in cucumber floral sex determination.

Amino Acid Sequence↗

PubMed2001

Spinal movement and performance of a standing reach task in participants with and without Parkinson disease.

BACKGROUND AND PURPOSE: Evidence suggests that individuals with early and mid-stage Parkinson disease (PD) have diminished range of motion (ROM). Spinal ROM influences the ability to function. In this investigation, the authors examined available spinal ROM, segmental excursions (the ROM used) during reaching, and their relationships in community-dwelling adults with and without PD. SUBJECTS: The subjects were 16 volunteers with PD (modified Hoehn and Yahr stages 1.5-3) and 32 participants without PD who were matched for age, body mass index, and sex. METHODS: Range of motion of the extremities was measured using a goniometer, and ROM of the spine was measured using the functional axial rotation (FAR) test, a measure of unrestricted cervico-thoracic-lumbar rotation in the seated position. Motion during reaching was determined using 3-dimensional motion analysis. Group differences were determined using multivariable analysis of variance followed by analysis of variance. Contributions to total reaching distance of segmental excursions (eg, thoracic rotation, thoracic lateral flexion) were determined using forward stepwise regression. RESULTS: Subjects with PD as compared with subjects without PD had less ROM (FAR of 98.2 degrees versus 110.3 degrees, shoulder flexion of 151.9 degrees versus 160.1 degrees) and less forward reaching (29.5 cm versus 34.0 cm). Lateral trunk flexion and total rotation relative to the ground contributed to reaching, with the regression model explaining 36% of the variance. DISCUSSION AND CONCLUSION: These results contribute to the growing body of evidence demonstrating that spinal ROM is impaired early in PD.

Adult↗

PubMed2002

Variation in coronary artery bypass grafting, angioplasty, cataract surgery, and hip replacement rates among primary care groups in London: association with population and practice characteristics.

BACKGROUND: Operation rates for common surgical procedures are known to vary widely both between areas within the same country and between countries. However, no studies in the United Kingdom have yet examined the variation in the use of important groups of surgical procedures among primary care groups. METHODS: Data were obtained from the NHS Executive and the Department of Health on each of the 66 primary care groups in London that existed on 1 April 1999. These were used to estimate indicators for six main groups of variables: population estimates, mortality rates, Census data, benefits data, practice characteristics, and hospital admissions. The data were used to generate a number of population and practice variables describing the characteristics of each primary care group in London. We also obtained information at ward level by age and sex on the number of patients admitted for coronary artery bypass grafting (CABG) and angioplasty (PTCA); cataract surgery; and hip replacement in patients aged 65 years and over during the period 1997-1998. These data were used with population estimates to estimate directly age-standardized annual operation rates for each primary care group for the study period. RESULTS: Operation rates for the three groups of procedures examined in this study varied widely between the 66 primary care groups. The directly standardized combined CABG and PtCA rate varied from 28 to 193 per 100,000 (mean 80); cataract surgery rates from 167 to 618 per 100,000 (mean 291); and hip replacement in people aged 65 years and over from 74 to 363 per 100,000 (mean 202). Correlations between operation rates and population and practice variables were relatively weak. Multifactorial models explained 57 per cent of the variation in CABG and PTCA rates, 34 per cent of the variation in cataract surgery rates, and 27 per cent of the variation in hip replacement rates. CONCLUSIONS: There are wide variations in the operation rates for important groups of surgical procedures among primary care groups. These variations are poorly explained by differences in the population and practice characteristics of primary care groups. The underlying reasons for variations in operation rates need to be better understood if the ambitious targets for access to elective surgery outlined in the NHS plan are to be met.

Aged↗