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BACKGROUND: Parents often underuse dental care services for their children with early childhood caries (ECC), resulting in a high burden of untreated dental caries. AIM: To describe parental perceptions and challenges in dental care utilization for their children with ECC. DESIGN: A descriptive qualitative study was conducted with parents of children with ECC seeking dental care in Mangalore, India. Data were collected through focus group discussions using an interview guide. Manual line-by-line coding and content analysis methods were used for data analysis. RESULTS: Three categories were generated from data obtained through 5 focus groups of 27 participants: dental care visiting patterns, the significance of dental visits, and challenges to dental care utilization. Parents would only visit the dentist when they perceived their children's tooth problems. The challenges faced include time constraints, misinformation, lack of awareness and motivation, costs, fear, and anxiety of the children and the parents themselves. Parents perceived improvements in the awareness of their children's oral health and quality of life after dental visits. CONCLUSION: Attending dental services to treat their children's tooth problems was the primary way of attaining awareness about prevention among the parents of children with ECC. Increased oral health awareness and improved quality of life can motivate parents to seek further dental care for their children. Collaboration with multidisciplinary stakeholders is required to improve oral health awareness among parents of children with ECC. KNOWLEDGE TRANSFER STATEMENT: The study's results will help plan targeted preventive programs for children with ECC. The study suggests dental care utilization by children with ECC is based on parental perceptions of their children's tooth problems. It outlines the challenges that affect dental visits of children with ECC and the role of multidisciplinary stakeholders. Improved oral health awareness and quality of life following dental treatment can facilitate further dental visits.
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OBJECTIVE: To describe the early feeding, weaning, and oral hygiene practices of children with early childhood caries (ECC), their parents' knowledge and attitudes regarding infant feeding, and the feeding-related challenges faced by the parents. METHODS: This descriptive qualitative study involved parents of children with ECC who sought dental treatment at an academic dental college in India. Data were collected though focus groups conducted with the 27 parents of children with ECC, using a focus group discussion guide. Data were analyzed using the content analysis method. RESULTS: Community norms, such as learning from the older women in the families or neighborhoods, guided the feeding method, duration of feeding, and weaning. Breastfeeding or bottle-feeding at bedtime beyond 12 mo of age and feeding sugary drinks during weaning were standard practices, despite knowing the risk for dental caries. Parents faced multiple challenges regarding weaning and were unaware of the significance of infant oral hygiene practices. CONCLUSION: In children with ECC, infant feeding practices included prolonged breastfeeding or bottle-feeding beyond the required age, feeding at bedtime, and feeding sugary drinks. Although the parents knew that these feeding habits could increase the risk for caries, they lacked the self-efficacy to translate their knowledge into action during weaning. Also, they lacked awareness regarding infant oral hygiene practices. KNOWLEDGE TRANSFER STATEMENT: The study provides information on the feeding habits of infants that can increase the risk for caries, the challenges faced by the parents of these children in altering these risky habits, and their lack of knowledge on infant oral hygiene practices. Policy/decision makers can advocate for pediatricians and pediatric dentists to incorporate anticipatory guidance or motivational interviewing techniques to tailor the preventive program for ECC for Indian children.
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Caries Dental , Lactante , Humanos , Preescolar , Niño , Femenino , Anciano , Caries Dental/prevención & control , Destete , Susceptibilidad a Caries Dentarias , Prevalencia , Higiene BucalRESUMEN
AIM: The overall goal of the present study was to contribute to consistency in the provincial approach to survivorship care planning through knowledge synthesis and exchange. Our review focused on the research concerning the physical and emotional challenges of breast cancer (bca) patients and survivors and the effects of the interventions that have been used for lessening those challenges. METHODS: The psychosocial topics identified in bca survivorship care plans created by two different initiatives in our province provided the platform for our search criteria: quality of life (qol), sexual function, fatigue, and lifestyle behaviours. We conducted an umbrella review to retrieve the best possible evidence, and only reviews investigating the intended outcomes in bca survivors and having moderate-to-high methodologic quality scores were included. RESULTS: Of 486 reports retrieved, 51 reviews met the inclusion criteria and form part of the synthesis. Our results indicate that bca patients and survivors experience numerous physical and emotional challenges and that interventions such as physical activity, psychoeducation, yoga, and mindfulness-based stress reduction are beneficial in alleviating those challenges. CONCLUSIONS: Our study findings support the existing survivorship care plans in our province with respect to the physical and emotional challenges that bca survivors often face. However, the literature concerning cancer risks specific to bca survivors is scant. Although systematic reviews are considered to be the "gold standard" in knowledge synthesis, our findings suggest that much remains to be done in the area of synthesis research to better guide practice in cancer survivorship.
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We aimed to investigate the levels of anxiety, depression, satisfaction with information provision and cancer-related knowledge in partners of head and neck cancer (HNC) patients receiving a Multimode Comprehensive Tailored Information Package (MCTIP). A non-randomised, controlled trial was conducted with partners of HNC patients recruited at two academic hospitals in Montreal. The Test participants received the MCTIP, while the Control participants received information in an ad hoc manner. All participants were evaluated using the Hospital Anxiety and Depression Scale (HADS), Satisfaction with Cancer Information Profile and a cancer knowledge questionnaire at baseline, and 3 and 6 months later. Data were analysed using descriptive statistics, t-test and chi-square test, and mixed model analysis to test the impact of the intervention. A total of 31 partners of HNC patients participated in this study and completed all the evaluations. The partners in the Test group experienced significantly lower levels of anxiety (P = 0.001) and depression (P = 0.003) symptoms and were more satisfied (P = 0.002) with cancer information provided than partners in the Control group. Providing tailored information seems to have positive outcomes regarding anxiety, depression, and satisfaction in partners of HNC patients. Larger randomised studies are warranted to validate these effects.
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Neoplasias de Cabeza y Cuello/psicología , Multimedia , Parejas Sexuales/psicología , Ansiedad/etiología , Depresión/psicología , Femenino , Educación en Salud , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Persona de Mediana Edad , Satisfacción Personal , Calidad de VidaRESUMEN
AIM: In the present study, we synthesized the published literature about the psychosocial aspects of colorectal cancer (crc) survivorship to support an update of the evidentiary base of the survivorship care plans (scps) created in our jurisdiction. METHODS: The psychosocial topics identified in the crc scps created by two different initiatives in our province were used as search criteria: quality of life (qol), sexual function, fatigue, and lifestyle behaviors. An umbrella review was conducted to retrieve the best possible evidence. Only reviews that investigated the intended outcomes in crc survivors and those with moderate-to-high methodologic quality scores were included. RESULTS: Of 462 retrieved reports, eight reviews met the inclusion criteria for the synthesis. Of those eight, six investigated the challenges of crc survivors and two investigated the effect of physical activity on survivor well-being. Our results indicate that emotional and physical challenges are common in crc survivors and that physical activity is associated with clinically important benefits for the fatigue and physical functioning of crc survivors. CONCLUSIONS: Our study findings update the evidence and indicate that existing scps in our province concerning the physical and emotional challenges of crc survivors reflect the evidence at the time of their issue. However, the literature concerning cancer risks specific to crc survivors is lacking. Although systematic reviews are considered to be the "gold standard" in knowledge synthesis, our findings suggest that much remains to be done in the area of synthesis research to better guide practice in cancer survivorship.
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During pregnancy, oxidative stress has been implicated in the pathophysiology of preeclampsia and preterm birth leading to poor birth outcome. Hyperhomocysteinemia caused as a consequence of altered micronutrients like folic acid and vitamin B12 is associated with increased production of reactive oxygen species that generate oxidative stress. These micronutrients are important determinants of methyl donor, s-adenosyl methionine while phospholipids are important methyl acceptors in the one-carbon metabolic cycle. A series of our studies in women during pregnancy have demonstrated altered levels of these micronutrients and the negative association of docosahexaenoic acid with homocysteine. Various strategies to counteract oxidative stress during pregnancy such as antioxidant therapy have been examined and found to be inconsistent. In this review, we focus on the role of oxidative stress in pregnancy and discuss the possibility of ameliorating it through modulation of maternal micronutrients and omega 3 fatty acids especially docosahexaenoic acid. We propose for the first time that manipulation of one-carbon metabolism by maternal diet could be a potential mechanism to counteract oxidative stress through homocysteine lowering effects and help in reducing the risk for adverse pregnancy outcomes.
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Ácidos Grasos Omega-3/farmacología , Micronutrientes/farmacología , Estrés Oxidativo/efectos de los fármacos , Carbono/metabolismo , Dieta , Ácidos Docosahexaenoicos/farmacología , Femenino , Humanos , Preeclampsia/etiología , Preeclampsia/metabolismo , Embarazo , Nacimiento Prematuro , Especies Reactivas de Oxígeno/metabolismoRESUMEN
OBJECTIVE: Except for a single case report, musical ear syndrome in cochlear implantees has not been studied. We aimed to study the prevalence and nature of musical ear syndrome among adult cochlear implant patients, as well as the effect on their emotional well-being. STUDY DESIGN, PATIENTS AND INTERVENTION: A cross-sectional survey of patients aged 18 years and above who had received cochlear implants for profound hearing loss between 1997 and 2010. RESULTS: Of the 82 patients studied, 18 (22 per cent) were found to have experienced musical ear syndrome. Seven and 11 patients had musical ear syndrome prior to and after cochlear implantation, respectively. The character of musical ear syndrome symptoms was described as instrumental music (n = 2), singing (6) or both (10). Fourteen patients reported an adverse emotional effect, with three expressing 'intolerance'. CONCLUSIONS: In this study, 22 per cent of cochlear implantees experienced musical ear syndrome. These symptoms affected patients' emotional state, but most coped well. Musical ear syndrome can occur prior to and after cochlear implantation.
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Percepción Auditiva , Implantes Cocleares/efectos adversos , Sordera/fisiopatología , Alucinaciones/psicología , Música/psicología , Estimulación Acústica , Adolescente , Adulto , Estudios Transversales , Sordera/rehabilitación , Femenino , Alucinaciones/patología , Humanos , Masculino , Persona de Mediana Edad , Reconocimiento en Psicología , Encuestas y Cuestionarios , Adulto JovenRESUMEN
OBJECTIVES: To investigate the impact of a Multimode Comprehensive Tailored Information Package (MCTIP) on Head and Neck (H&N) cancer patients' knowledge and satisfaction. METHODS: A non-randomized controlled trial was conducted at two participating hospitals. One hospital delivered the MCTIP and the second hospital provided normal care. The study was approved by local ethical committees. Patients with Stage III and IV cancer in the H&N region were recruited between their diagnosis and treatment. All participants were evaluated at baseline, 3 and 6months later using the Satisfaction with Cancer Information Profile (SCIP) and a Cancer Knowledge questionnaire. Data were analyzed using descriptive statistics, T tests, chi square tests and finally linear mixed model analyses to test the potential impact of the intervention. RESULTS: A total of 103 participants participated in this study and complete data at all time points were collected for 96. The Test group reported higher levels of Cancer Knowledge and Satisfaction at all time points (p<0.001 with all comparisons) compared to the Control group. CONCLUSION: Our study demonstrated an association between receiving the multimedia based tailored information and higher levels of satisfaction and cancer knowledge compared to those who receive information in ad hoc manner. IMPLICATIONS: Exploring patients' informational needs is necessary before planning information services to them.
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Neoplasias de Cabeza y Cuello/psicología , Servicios de Información , Satisfacción del Paciente , Anciano , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVE: To investigate if tailored information provision decreases symptoms of anxiety and depression in late stage Head and Neck (H&N) cancer patients. METHODS: This non-randomized, controlled trial was conducted with stage III or IV H&N cancer patients. Subjects were recruited at two academic health centers in Montreal. At the test center, subjects received the Multimode Comprehensive Tailored Information Package (MCTIP), while at the control center, they received normal information provision. Participants were evaluated using the Hospital Anxiety and Depression Scale (HADS) at baseline and 3 and 6 month later. Data were analyzed using descriptive statistics then T tests and chi square tests to compare group differences and finally mixed model analysis to test differences in outcome variables. RESULTS: A total of 103 subjects were recruited and of them 96 (47 tests and 49 controls) participants completed baseline, 3 and 6 month evaluations. The test group experienced lower levels of anxiety (p = 0.001) and depression (p = 0.089) than the control group. CONCLUSION: The subjects receiving tailored information had lower levels of anxiety than their counterparts. In addition, depression showed a reduction in the expected direction in the test group. PRACTICE IMPLICATIONS: Our results need to be further confirmed using a randomized approach in different samples but they suggest benefits for stage III and IV H&N cancer patients receiving tailored, multi-modal information concerning their cancer.
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Ansiedad/prevención & control , Depresión/prevención & control , Neoplasias de Cabeza y Cuello/psicología , Multimedia , Educación del Paciente como Asunto/clasificación , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Ansiedad/psicología , Recursos Audiovisuales , Gráficos por Computador , Bases de Datos Factuales , Depresión/psicología , Empleo , Femenino , Estudios de Seguimiento , Neoplasias de Cabeza y Cuello/terapia , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/psicología , Recurrencia Local de Neoplasia/terapia , Estadificación de Neoplasias , Folletos , Estudios Prospectivos , Estrés Psicológico/prevención & control , Interfaz Usuario-Computador , Grabación de Videodisco , Adulto JovenRESUMEN
Abnormal brain development in a compromised prenatal and/or early postnatal environment is thought to be a risk factor for several neurobehavioural disorders. However, the mechanisms underlying these are not well understood. We have earlier reported reduced placental docosahexaenoic acid (DHA) levels in preterm deliveries. We have hypothesized that increased oxidative stress and reduced DHA levels may lead to changes in the circulating levels of maternal and cord brain-derived neurotrophic factor (BDNF) and its receptor tyrosine kinase B (TrkB) levels. A total number of 96 women delivering preterm and 95 women delivering at term were recruited. Plasma BDNF levels were measured in both mother and cord blood plasma using the BDNF Immuno Assay kit. Placental TrkB levels were analysed using sandwich enzyme-linked immunosorbent assay (ELISA). Maternal plasma BDNF levels and placental TrkB levels were higher (p<0.05) while cord plasma BDNF levels were lower (p<0.01) in women delivering preterm as compared to term. There was a negative association between levels of placental TrkB and DHA (p=0.034). A negative association between maternal plasma BDNF levels and placental weight (p=0.001) was observed while a positive association was seen between cord plasma BDNF levels and gestation (p=0.025). The reduction in cord BDNF levels may have implications for altered neurodevelopment in childhood and later life. Studies need to be undertaken to follow up children born preterm for risk of neurobehavioural disorders like attention deficit hyperactivity disorder (ADHD) to understand the effect of altered BDNF at birth on neurodevelopment.
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Factor Neurotrófico Derivado del Encéfalo/metabolismo , Placenta/metabolismo , Receptor trkB/metabolismo , Adulto , Encéfalo/metabolismo , Ácidos Docosahexaenoicos/metabolismo , Femenino , Sangre Fetal/metabolismo , Humanos , Recién Nacido , Recien Nacido Prematuro , Embarazo , Adulto JovenRESUMEN
Castleman's disease of the parotid gland is an extremely rare entity, with fewer than 20 cases reported in world literature so far and only 1 previous case report describing the ultrasound findings. The Doppler findings of parotid Castleman's disease have never been described before to the best of the authors' knowledge. This report describes the ultrasonographic and Doppler findings in a histopathologically proven case of Castleman's disease of the left parotid gland in a young man.
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Enfermedad de Castleman/diagnóstico por imagen , Enfermedades de las Parótidas/diagnóstico por imagen , Humanos , Masculino , Ultrasonografía Doppler en Color , Adulto JovenRESUMEN
Murine leukemia virus (MLV) is currently the most widely used gene delivery system in gene therapy trials. The simple retrovirus packages two copies of its RNA genome by a mechanism that involves interactions between the nucleocapsid (NC) domain of a virally-encoded Gag polyprotein and a segment of the RNA genome located just upstream of the Gag initiation codon, known as the Psi-site. Previous studies indicated that the MLV Psi-site contains three stem loops (SLB-SLD), and that stem loops SLC and SLD play prominent roles in packaging. We have developed a method for the preparation and purification of large quantities of recombinant Moloney MLV NC protein, and have studied its interactions with a series of oligoribonucleotides that contain one or more of the Psi-RNA stem loops. At RNA concentrations above approximately 0.3 mM, isolated stem loop SLB forms a duplex and stem loops SL-C and SL-D form kissing complexes, as expected from previous studies. However, neither the monomeric nor the dimeric forms of these isolated stem loops binds NC with significant affinity. Longer constructs containing two stem loops (SL-BC and SL-CD) also exhibit low affinities for NC. However, NC binds with high affinity and stoichiometrically to both the monomeric and dimeric forms of an RNA construct that contains all three stem loops (SL-BCD; K(d)=132(+/-55) nM). Titration of SL-BCD with NC also shifts monomer-dimer equilibrium toward the dimer. Mutagenesis experiments demonstrate that the conserved GACG tetraloops of stem loops C and D do not influence the monomer-dimer equilibrium of SL-BCD, that the tetraloop of stem loop B does not participate directly in NC binding, and that the tetraloops of stem loops C and D probably also do not bind to NC. These surprising results differ considerably from those observed for HIV-1, where NC binds to individual stem loops with high affinity via interactions with exposed residues of the tetraloops. The present results indicate that MLV NC binds to a pocket or surface that only exists in the presence of all three stem loops.
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Genoma Viral , Virus de la Leucemia Murina de Moloney/genética , Virus de la Leucemia Murina de Moloney/metabolismo , Nucleocápside/metabolismo , ARN Viral/metabolismo , Secuencias Reguladoras de Ácidos Nucleicos/genética , Ensamble de Virus , Secuencia de Aminoácidos , Secuencia de Bases , Calorimetría , Secuencia Conservada/genética , Dimerización , Electroforesis en Gel de Poliacrilamida , Espectroscopía de Resonancia Magnética , Modelos Biológicos , Datos de Secuencia Molecular , Virus de la Leucemia Murina de Moloney/química , Conformación de Ácido Nucleico , Nucleocápside/genética , Nucleocápside/aislamiento & purificación , Mutación Puntual/genética , Unión Proteica , Sitios de Empalme de ARN/genética , ARN Viral/química , ARN Viral/genética , ARN Viral/aislamiento & purificación , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Soluciones , Temperatura , TermodinámicaRESUMEN
The Co and Fe K-edge extended X-ray absorption fine structure (EXAFS) spectra of the methionyl aminopeptidase from Escherichia coli (EcMetAP) have been recorded in the presence of 1 and 2 equiv of either Co(II) or Fe(II) (i.e., [Co(II)_(EcMetAP)], [Co(II)Co(II)(EcMetAP)], [Fe(II)_(EcMetAP)], and [Fe(II)Fe(II)(EcMetAP)]). The Fourier transformed data of both [Co(II)_(EcMetAP)] and [Co(II)Co(II)(EcMetAP)] are dominated by a peak at ca. 2.05 A, which can be fit assuming 5 light atom (N,O) scatterers at 2.04 A. Attempts to include a Co-Co interaction (in the 2.4-4.0 A range) in the curve-fitting parameters were unsuccessful. Inclusion of multiple-scattering contributions from the outer-shell atoms of a histidine-imidazole ring resulted in reasonable Debye-Waller factors for these contributions and a slight reduction in the goodness-of-fit value (f '). These data suggest that a dinuclear Co(II) center does not exist in EcMetAP and that the first Co atom is located in the histidine-ligated side of the active site. The EXAFS data obtained for [Fe(II)_(EcMetAP)] and [Fe(II)Fe(II)(EcMetAP)] indicate that Fe(II) binds to EcMetAP in a similar site to Co(II). Since no X-ray crystallographic data are available for any Fe(II)-substituted EcMetAP enzyme, these data provide the first glimpse at the Fe(II) active site of MetAP enzymes. In addition, the EXAFS data for [Co(II)Co(II)(EcMetAP)] incubated with the antiangiogenesis drug fumagillin are also presented.
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Aminopeptidasas/química , Escherichia coli/enzimología , Hierro/metabolismo , Metaloendopeptidasas/química , Absorciometría de Fotón , Aminopeptidasas/aislamiento & purificación , Inhibidores de la Angiogénesis/farmacología , Sitios de Unión , Cobalto/química , Cobalto/metabolismo , Electroforesis en Gel de Poliacrilamida , Activación Enzimática , Histidina/química , Humanos , Imidazoles/química , Hierro/química , Cinética , Metaloendopeptidasas/metabolismo , Metionil Aminopeptidasas , Modelos Químicos , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Genetic mapping studies in bipolar disorder (BD) have been hampered by the unclear boundaries of the phenotypic spectrum, and possibly, by the complexity of the underlying genetic mechanisms, and heterogeneity. Among the suggested approaches to circumvent these problems, a pharmacogenetic strategy has been increasingly proposed. Several studies have indicated that patients with BD who respond well to lithium prophylaxis constitute a biologically distinct subgroup. In this study we have conducted a complete genome scan using 378 markers spaced at an average distance of 10 cM in 31 families ascertained through excellent lithium responders. Response to lithium was evaluated prospectively with an average follow-up of 12 years. Evidence for linkage was found with a locus on chromosome 15q14 (ACTC, lod score = 3.46, locus-specific P-value = 0.000014) and suggestive results were observed for another marker on chromosome 7q11.2 (D7S1816, lod score = 2.68, locus-specific P-value = 0.00011). Other interesting findings were obtained with markers on chromosomes 6 and 22, namely D6S1050 (lod score = 2.0, locus-specific P-value = 0.00004) and D22S420 (lod score = 1.91). Nonparametric linkage analysis provided additional support for the role of these loci. Further analyses of these results suggested that the locus on chromosome 15q14 may be implicated in the etiology of BD, whereas the 7q11.2 locus may be relevant for lithium response. In conclusion, our results provide original evidence suggesting that loci on 15q14 and 7q11.2 may be implicated in the pathogenesis of BD responsive to lithium.
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Trastorno Bipolar/tratamiento farmacológico , Trastorno Bipolar/genética , Mapeo Cromosómico , Cromosomas Humanos Par 15 , Cromosomas Humanos Par 7 , Predisposición Genética a la Enfermedad , Litio/uso terapéutico , Adulto , Edad de Inicio , Antimaníacos/uso terapéutico , Femenino , Estudios de Seguimiento , Genes Dominantes , Genes Recesivos , Ligamiento Genético , Marcadores Genéticos , Genoma Humano , Humanos , Masculino , Persona de Mediana Edad , Modelos Genéticos , Modelos Estadísticos , Programas Informáticos , Factores de TiempoRESUMEN
The fission yeast Schizosaccharomyces pombe undergoes cell division through a medially placed actomyosin-based contractile ring. One of the key components of this ring is the F-actin based motor protein myosin II. The myosin II heavy chain Myo2p has two light-chain-binding domains, IQl and IQ2, which bind the essential light chain, Cdc4p, and the regulatory light chain, Rlc1p. Previously, we have reported the characterization of cells expressing Myo2p lacking the IQ2 domain that facilitates Myo2p interaction with Rlc1p. In this study, we have created and characterized S. pombe strains carrying precise deletions of IQ1 and the entire neck region encompassing the IQ1 and IQ2 domains. Surprisingly, we found that the entire neck region of Myo2p is dispensable for Myo2p function. Cells deleted for IQ1, IQ2 and the entire neck region of Myo2p do not display any obvious cytoskeletal abnormalities. Immunofluorescence studies indicated that Cdc4p localizes at the ring in early and late mitotic cells in a strain in which interactions of Cdc4p with both the myosin II heavy chains (Myo2p and Myp2p) are abolished. Unlike mutations in Rlc1p that are suppressed by a simultaneous deletion of its binding site on Myo2p, mutations in the essential light chain Cdc4p are not suppressed by deletion of its binding sites on Myo2p, suggesting that Cdc4p may have additional partners essential for cytokinesis. Consistent with this, we provide evidence that two other IQ-domain containing actomyosin ring proteins, Rng2p (an IQGAP-related protein) and Myo51p (a type V myosin heavy chain), physically interact with Cdc4p. We concluded that Cdc4p, a novel myosin light chain, interacts with multiple actomyosin ring components to effect cytokinesis.
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Proteínas de Ciclo Celular/metabolismo , Proteínas F-Box , Proteínas Activadoras de GTPasa , Cadenas Pesadas de Miosina/metabolismo , Miosina Tipo II/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Ubiquitina-Proteína Ligasas , Sitios de Unión , Proteínas de Ciclo Celular/genética , División Celular/fisiología , Proteínas del Citoesqueleto , Proteínas Fúngicas/metabolismo , Inmunohistoquímica , Cadenas Pesadas de Miosina/genética , Miosina Tipo II/genética , Estructura Terciaria de Proteína , Schizosaccharomyces/citología , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genéticaRESUMEN
The metal-binding properties of the methionyl aminopeptidase from Escherichia coli (MetAP) were investigated. Measurements of catalytic activity as a function of added Co(II) and Fe(II) revealed that maximal enzymatic activity is observed after the addition of only 1 equiv of divalent metal ion. Based on these studies, metal binding constants for the first metal binding event were found to be 0.3 +/- 0.2 microM and 0.2 +/- 0.2 microM for Co(II)- and Fe(II)-substituted MetAP, respectively. Binding of excess metal ions (>50 equiv) resulted in the loss of approximately 50% of the catalytic activity. Electronic absorption spectral titration of a 1 mM sample of MetAP with Co(II) provided a binding constant of 2.5 +/- 0.5 mM for the second metal binding site. Furthermore, the electronic absorption spectra of Co(II)-loaded MetAP indicated that both metal ions reside in a pentacoordinate geometry. Consistent with the absorption data, electron paramagnetic resonance (EPR) spectra of [CoCo(MetAP)] also indicated that the Co(II) geometries are not highly constrained, suggesting that each Co(II) ion in MetAP resides in a pentacoordinate geometry. EPR studies on [CoCo(MetAP)] also revealed that at pH 7.5 there is no significant spin-coupling between the two Co(II) ions, though a small proportion ( approximately 5%) of the sample exhibited detectable spin-spin interactions at pH values > 9.6. EPR studies on [Fe(III)_(MetAP)] and [Fe(III)Fe(III)(MetAP)] also suggested no spin-coupling between the two metal ions. (1)H nuclear magnetic resonance (NMR) spectra of [Co(II)_(MetAP)] in both H(2)O and D(2)O buffer indicated that the first metal binding site contains the only active-site histidine residue, His171. Mechanistic implications of the observed binding properties of divalent metal ions to the MetAP from E. coli are discussed.
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Aminopeptidasas/química , Aminopeptidasas/metabolismo , Cobalto/química , Cobalto/metabolismo , Hierro/química , Hierro/metabolismo , Sitios de Unión , Catálisis , Cationes Bivalentes/química , Cationes Bivalentes/metabolismo , Relación Dosis-Respuesta a Droga , Espectroscopía de Resonancia por Spin del Electrón , Metionil Aminopeptidasas , Resonancia Magnética Nuclear Biomolecular , Unión Proteica , Espectrofotometría UltravioletaRESUMEN
AIM: To gain further evidence of the psychometric properties of the Modified Dental Anxiety Scale. SETTING: Dental admission clinics. DESIGN: Consecutive sampling, cross-sectional survey. PARTICIPANTS: Patients (n = 800) in four cities (Belfast, Northern Ireland; Helsinki, Finland; Jyväskylä, Finland and Dubai, UAE). METHODS: Questionnaire booklet handed to patients, attending clinics, for completion following an invitation by the researcher to be included in the study. MEASURES: Modified Dental Anxiety Scale (MDAS), together with further questions concerning dental attendance and nervousness about dental procedures. RESULTS: Overall 9.3 per cent of patients indicated high dental anxiety. MDAS showed high levels of internal consistency, and good construct validity. The relationship of dental anxiety with age was similar to previous reports and showed lowered anxiety levels in older patients. CONCLUSION: Data from three countries has supported the psychometric properties of this modified and brief dental anxiety scale.
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Ansiedad al Tratamiento Odontológico/diagnóstico , Escala de Ansiedad Manifiesta , Adolescente , Adulto , Factores de Edad , Anciano , Análisis de Varianza , Comparación Transcultural , Estudios Transversales , Ansiedad al Tratamiento Odontológico/epidemiología , Finlandia/epidemiología , Humanos , Modelos Lineales , Persona de Mediana Edad , Irlanda del Norte/epidemiología , Prevalencia , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Emiratos Árabes Unidos/epidemiologíaRESUMEN
Blood RBC's were used to study the role of polyamines, putrescine, spermidine and spermine individually as antioxidants against the peroxidative action of H(2)O(2) which leads to haemolysis of erythrocytes. Results indicated that putrescine did not act as antioxidant at all concentrations used in our studies. However, spermidine and spermine suppressed peroxidative changes in RBC's due to the action of H(2)O(2) and this suppression was greater with higher concentration of these individual polyamines used, separately. Further, all the three polyamines decreased haemolysis of erythrocytes at all concentrations studied. The action of putrescine to suppress haemolysis of RBC's without showing antioxidant property hypothetically suggests that these properties of respective polyamines may have independent mechanism of action.
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Blood erythrocytes of 25 confirrhed malarial patients infested with P. vivax were analyzed for peroxidation and hemolysis and results compared with 10 uninfected normal control samples. Results indicated significant increase in peroxide formation measured as malondialdehyde, both in presence and absence of H2O2, in parasite infested erythrocytes. These changes induced hemolysis of infected erythrocytes which was increased manifold in presence of H2O2 and could probably be the reason for extensive anemia reported in malaria.
Asunto(s)
Eritrocitos/parasitología , Hemólisis , Peroxidación de Lípido , Plasmodium vivax/fisiología , Animales , HumanosRESUMEN
The identity of the physiologically relevant metal ions for the methionyl aminopeptidase (MetAP) from Escherichia coli was investigated and is suggested to be Fe(II). The metal content of whole cells in the absence and presence of expression of the type I MetAP from E. coli was determined by inductively coupled plasma (ICP) emission analysis. The observed change in whole cell concentrations of cobalt, cadmium, copper, nickel, strontium, titanium, and vanadium upon expression of MetAP was negligible. On the other hand, significant increases in the cellular metal ion concentrations of chromium, zinc, manganese, and iron were observed with the increase in iron concentration being 4.4 and 6.2 times greater than that of manganese and zinc, respectively. Activity assays of freshly lysed BL21(DE3) cells containing the pMetAAP plasmid revealed detectable levels (>2 units/mg) of MetAP activity. Control experiments with BL21(DE3) without the MetAP plasmid showed no detectable enzymatic activity. Since MetAP is active upon expression, these data strongly suggest that cobalt is not the in vivo metal ion for the MetAP from E. coli. The MetAP from E. coli as purified was found to be catalytically inactive (=2 units/mg). ICP emission analysis of the as-purified enzyme revealed no catalytically relevant metal ions. Both the Co(II)- and Fe(II)-MetAP enzymes are susceptible to autoxidation, so strict care must be taken to remove all dissolved oxygen. Enzymatic assays performed under anaerobic conditions indicated that of the di- and trivalent metal cations tested to date, only Co(II) (37.3 units/mg), Fe(II) (29.7 units/mg), Mn(II) (7.0 units/mg), and Zn(II) (3.3 units/mg) provided detectable levels of enzymatic activity. In each case, excess metal ions were found to be inhibitory. The observed specific activity of Co(II)-MetAP is more than 3 times greater than that previously reported for the MetAP from E. coli [Ben-Bassat, A., et al. (1987) J. Bacteriol. 169, 751-757]. This increase in activity is likely due to the strict exclusion of air from reaction samples. Oxidation of either the Fe(II) or Co(II) form of the enzyme resulted in the complete loss of catalytic activity. The substrate binding constants (K(m)) for Met-Gly-Met-Met binding to the Co(II)- or Fe(II)-substituted MetAP enzymes, under anaerobic conditions, were found to be 3.16 and 1.95 mM, respectively. The combination of these data suggests that the in vivo metal ions for the MetAP enzyme from E. coli are likely Fe(II) ions.