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SignificanceThe modulation of growth hormone secretagogue receptor-1a (GHSR1a) signaling is a promising strategy for treating brain conditions of metabolism, aging, and addiction. GHSR1a activation results in pleiotropic physiological outcomes through distinct and pharmacologically separable G protein- and ß-arrestin (ßarr)-dependent signaling pathways. Thus, pathway-selective modulation can enable improved pharmacotherapeutics that can promote therapeutic efficacy while mitigating side effects. Here, we describe the discovery of a brain-penetrant small molecule, N8279 (NCATS-SM8864), that biases GHSR1a conformations toward Gαq activation and reduces aberrant dopaminergic behavior in mice. N8279 represents a promising chemical scaffold to advance the development of better treatments for GHSR1a-related brain disorders involving the pathological dysregulation of dopamine.
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Encéfalo/metabolismo , Dopamina/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/metabolismo , Receptores de Ghrelina/metabolismo , Animales , Dopamina/genética , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/genética , Masculino , Ratones , Ratones Noqueados , Receptores de Ghrelina/genéticaRESUMEN
We benchmark a set of quantum-chemistry methods, including multitrajectory Ehrenfest, fewest-switches surface-hopping, and multiconfigurational-Ehrenfest dynamics, against exact quantum-many-body techniques by studying real-time dynamics in the Holstein model. This is a paradigmatic model in condensed matter theory incorporating a local coupling of electrons to Einstein phonons. For the two-site and three-site Holstein model, we discuss the exact and quantum-chemistry methods in terms of the Born-Huang formalism, covering different initial states, which either start on a single Born-Oppenheimer surface, or with the electron localized to a single site. For extended systems with up to 51 sites, we address both the physics of single Holstein polarons and the dynamics of charge-density waves at finite electron densities. For these extended systems, we compare the quantum-chemistry methods to exact dynamics obtained from time-dependent density matrix renormalization group calculations with local basis optimization (DMRG-LBO). We observe that the multitrajectory Ehrenfest method, in general, only captures the ultrashort time dynamics accurately. In contrast, the surface-hopping method with suitable corrections provides a much better description of the long-time behavior but struggles with the short-time description of coherences between different Born-Oppenheimer states. We show that the multiconfigurational Ehrenfest method yields a significant improvement over the multitrajectory Ehrenfest method and can be converged to the exact results in small systems with moderate computational efforts. We further observe that for extended systems, this convergence is slower with respect to the number of configurations. Our benchmark study demonstrates that DMRG-LBO is a useful tool for assessing the quality of the quantum-chemistry methods.
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BACKGROUND: Women who smoke during pregnancy make less use of prenatal care; the relation of smoking behavior with the use of other forms of maternal healthcare is unknown. The objective of this study is to investigate the association between women's smoking behavior and their use of healthcare during pregnancy, birth and six weeks postpartum. METHODS: We analyzed data from the Dutch Midwifery Case Registration System (VeCaS), period 2012-2019. We included women with a known smoking status, singleton pregnancies, and who had their first appointment before 24 weeks of gestation with the primary care midwife. We compared three groups: non-smokers, early stoppers (stopped smoking in the first trimester), and late- or non-stoppers (stopped smoking after the first trimester or continued smoking). Descriptive statistics were used to report maternal healthcare utilization (during pregnancy, birth and six weeks postpartum), statistical differences between the groups were calculated with Kruskal-Wallis tests. Multivariable logistic regression was conducted to assess the association between smoking behavior and referrals to primary, secondary or tertiary care. RESULTS: We included 41 088 pregnant women. The groups differed significantly on maternal healthcare utilization. The late- or non-stoppers initiated prenatal care later and had less face-to-face consultations with primary care midwives during pregnancy. Compared to the non-smokers, the early- and late- or non-stoppers were statistically signficiantly more likely to be referred to the obstetrician during pregnancy and birth. Postpartum, the early- and late- or non-stoppers were statistically signficantly less likely to be referred to the obstetrician compared to the non-smokers. CONCLUSIONS: Although the early- and late- or non-stoppers initiated prenatal care later than the non-smokers, they did receive adequate prenatal care (according to the recommendations). The results suggest that not smoking during pregnancy may decrease the likelihood of referral to secondary or tertiary care. The large population of smokers being referred during pregnancy underlines the important role of the collaboration between healthcare professionals in primary and secondary or tertiary care. They need to be more aware of the importance of smoking as a medical and as a non-medical risk factor.
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Parto , Atención Prenatal , Estudios de Cohortes , Femenino , Humanos , Embarazo , Derivación y Consulta , Fumar/epidemiologíaRESUMEN
BACKGROUND: The Mothers Autonomy in Decision Making Scale (MADM) assesses women's autonomy and role in decision making. The Mothers on Respect Index (MORi) asseses women's experiences of respect when interacting with their healthcare providers. The Childbirth Experience Questionnaire 2.0 assesses the overall experience of childbirth (CEQ2.0). There are no validated Dutch measures of the quality of women's experiences in the intrapartum period. Therefore, the aim of this study was to evaluate the psychometric properties of these measures in their Dutch translations. METHODS: The available Dutch versions of the MADM and MORi were adapted to assess experiences in the intrapartum period. The CEQ2.0 was translated by using forward-backward procedures. The three measures were included in an online survey including items on individual characteristics (i.e. maternal, birth, birth interventions). Reliability was assessed by calculating Cronbach's alphas. Mann-Whitney, Kruskal Wallis or Student T-tests were applied where appropriate, to assess discrimination between women who differed on individual characteristics (known group validity). We hypothesized that women who experienced pregnancy complications and birth interventions would have statistically lower scores on the MADM, MORi and CEQ2.0, compared with women who had healthy pregnancies and physiological births. Convergent validity was assessed using Spearman Rank correlations between the MADM, MORi and/or CEQ2.0. We hypothesized moderate to strong correlations between these measures. Women's uptake of and feedback on the measures were tracked to assess acceptability and clarity. RESULTS: In total 621 women were included in the cross sectional study. The calculated Cronbach's alphas for the MADM, MORi and CEQ, were ≥ 0.77. Knowngroup validity was confirmed through significant differences on all relevant individual characteristics, except for vaginal laceration repair. Spearman Rank correlations ranged from 0.46-0.80. In total 98% of the included women out of the eligible population completed the MADM and MORi for each healthcare professional they encountered during childbirth. The proportions of MADM and MORi-items which were difficult to complete ranged from 0.0-10.8%, 0.6-2.7%, respectively. CONCLUSIONS: The results of our study showed that the Dutch version of the MADM, MORi and CEQ2.0 in Dutch are valid instruments that can be used to assess women's experiences in the intrapartum period.
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Trabajo de Parto/psicología , Parto/psicología , Atención Perinatal , Periodo Periparto/psicología , Psicometría , Encuestas y Cuestionarios , Adulto , Estudios Transversales , Toma de Decisiones , Femenino , Humanos , Países Bajos , Autonomía Personal , Embarazo , Reproducibilidad de los Resultados , Respeto , TraduccionesRESUMEN
BACKGROUND AND PURPOSE: Rhabdomyolysis is a medical emergency characterized by acute skeletal muscle breakdown with a sudden rise and subsequent fall of serum creatine kinase (CK) levels. Rhabdomyolysis events are provoked by exposure to external triggers, possibly in combination with an increased genetic susceptibility. We aimed to describe comprehensively the external triggers and potentially pathogenic genetic variants possibly implicated in increased rhabdomyolysis susceptibility. METHODS: We performed a retrospective single-center study, including a total of 1302 patients with an acute CK level exceeding 2000 IU/l. RESULTS: Anoxia was the most frequently reported trigger (40%). A subset of 193 patients were clinically suspected of an underlying genetic disorder (recurrent episodes, a positive family history, very high or persistently increased CK levels). In 72 of these patients, an unequivocal genetic defect was identified. A total of 22 genes with pathogenic variants were identified, including 52 different variants. Of those, 11 genes have been previously associated with rhabdomyolysis (ACADVL, ANO5, CPT2, DMD, DYSF, FKRP, HADHA, PGM1, LPIN1, PYGM, RYR1). Eleven genes are probably implicated in increased susceptibility (including AGL, CAPN3, CNBP, DMPK, MAGT1, ACADM, SCN4A, SGCA, SGCG, SMPD1, TANGO2). CONCLUSION: These findings suggest that the spectrum of genetic susceptibility for rhabdomyolysis has not yet been completely clarified. With the increasing availability of next-generation sequencing in a diagnostic setting, we expect that in more cases a genetic defect will be identified.
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Enfermedades Musculares , Rabdomiólisis , Anoctaminas , Predisposición Genética a la Enfermedad , Humanos , Músculo Esquelético , Canal de Sodio Activado por Voltaje NAV1.4 , Pentosiltransferasa , Estudios Retrospectivos , Rabdomiólisis/genéticaRESUMEN
A thorough characterization of base materials is the prerequisite for further research. In this paper, the characterization data of the reference materials (CEM I 42.5 R, limestone powder, calcined clay and a mixture of these three components) used in the second funding phase of the priority program 2005 of the German Research Foundation (DFG SPP 2005) are presented under the aspects of chemical and mineralogical composition as well as physical and chemical properties. The data were collected based on tests performed by up to eleven research groups involved in this cooperative program.
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BACKGROUND: Despite the health risks of smoking, some women continue during pregnancy. Professional smoking cessation support has shown to be effective in increasing the proportion of pregnant women who quit smoking. However, few women actually make use of professional support. AIM: To investigate the needs of women and their partners for professional smoking cessation support during pregnancy. METHODS: Semi-structured interviews were held with pregnant women and women who recently gave birth who smoked or quit smoking during pregnancy, and their partners, living in the north of the Netherlands. Recruitment was done via Facebook, LinkedIn, food banks, baby stores and healthcare professionals. The interviews were recorded, transcribed and thematically analysed. RESULTS: 28 interviews were conducted, 23 with pregnant women and women who recently gave birth, and five with partners of the women. The following themes were identified: 1) understanding women's needs, 2) responsibility without criticism, and 3) women and their social network. These themes reflect that women need support from an involved and understanding healthcare professional, who holds women responsible for smoking cessation but refrains from criticism. Women also prefer involvement of their social network in the professional support. CONCLUSION: For tailored support, the Dutch guideline for professional smoking cessation support may need some adaptations. The adaptations and recommendations, e.g. to involve women and their partners in the development of guidelines, might also be valuable for other countries. Women prefer healthcare professionals to address smoking cessation in a neutral way and to respect their autonomy in the decision to stop smoking.
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Cese del Hábito de Fumar , Atención a la Salud , Femenino , Humanos , Embarazo , Mujeres Embarazadas , Investigación Cualitativa , Fumar , Cese del Hábito de Fumar/métodosRESUMEN
BACKGROUND: Adolescents with intellectual disability (ID) (ID-adolescents) and adolescents with chronic diseases are both more likely to have emotional and behavioural problems. The aim of this study was to assess the association between chronic diseases in ID-adolescents and emotional and behavioural problems in a large school-based sample. METHODS: We obtained data on 1044 ID-adolescents, aged 12-18 years, attending secondary schools in the Netherlands. Parents of the adolescents completed the Dutch version of the Strengths and Difficulties Questionnaire and questions about chronic diseases in their child and about the background of the child. RESULTS: Prevalence rates of emotional and behavioural problems were generally high in ID-adolescents with chronic diseases (45%), compared with ID-adolescents without chronic diseases (17%). The likelihood of emotional and behavioural problems was high in ID-adolescents with two [odds ratios (OR) 4.47; 95% CI: 2.97-6.74] or more than two chronic diseases (OR 8.01; 95% CI: 5.18-12.39) and for ID-adolescents with mental chronic diseases (OR 4.56; 95% CI: 3.21-6.47). Also ID-adolescents with somatic chronic diseases had a high likelihood of emotional and behavioural problems (OR 1.99; 95% CI: 1.33-2.99), in particular in the combination of somatic and mental chronic diseases (OR 5.16; 95% CI: 3.46-7.71). CONCLUSIONS: The current study showed that chronic diseases in ID-adolescents, in particular mental chronic diseases, largely increase the likelihood of emotional and behavioural problems. This should be taken in the provision and planning of care for ID-adolescents.
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Síntomas Afectivos/epidemiología , Enfermedad Crónica/epidemiología , Discapacidad Intelectual/epidemiología , Trastornos Mentales/epidemiología , Adolescente , Síntomas Afectivos/diagnóstico , Síntomas Afectivos/psicología , Trastorno por Déficit de Atención con Hiperactividad/diagnóstico , Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Trastorno por Déficit de Atención con Hiperactividad/psicología , Niño , Enfermedad Crónica/psicología , Comorbilidad , Trastorno de la Conducta/diagnóstico , Trastorno de la Conducta/epidemiología , Trastorno de la Conducta/psicología , Estudios Transversales , Diagnóstico Dual (Psiquiatría) , Educación de las Personas con Discapacidad Intelectual , Femenino , Encuestas Epidemiológicas , Humanos , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/psicología , Funciones de Verosimilitud , Masculino , Trastornos Mentales/diagnóstico , Trastornos Mentales/psicología , Rehabilitación Vocacional , Riesgo , Trastorno de la Conducta Social/diagnóstico , Trastorno de la Conducta Social/epidemiología , Trastorno de la Conducta Social/psicologíaRESUMEN
PROBLEM: In the Netherlands there are no valid measurement tools available to measure respectful maternity care and women's autonomy. BACKGROUND: Respectful maternity care including women's autonomy during childbirth are key components of high quality care. AIM: This study aims to evaluate the applicability of the Canadian measures; the Mothers Autonomy in Decision Making (MADM) scale and the Mothers on Respect index (MORi) measures among pregnant women in the Netherlands. METHODS: We translated the measures MORi and MADM according to the WHO guidelines, adapted them to the Dutch health care system, evaluated their psychometric properties, and pilot tested before administration through an online cross-sectional survey. We assessed feasibility by calculating descriptive statistics on scores, and reliability by calculating Cronbach's alpha. The construct validity was measured by hypotheses on differences between subgroups based on maternal characteristics, pregnancy characteristics and healthcare provision. FINDINGS: Of 557 women included in the study, 83% experienced high respect and 62% experienced high autonomy. Both the MORi and MADM showed feasibility, internal consistency, and with respect to construct validity, both measures discriminated between type of care provision. Compared to women with pregnancy complications, those with a healthy pregnancy reported statistically higher MORi-scores. No differences were observed on MADM-scores. DISCUSSION: Both instruments can be used as quality of care measures aiming to improve care and thus experiences of women. CONCLUSION: The results of this study support the feasibility, reliability, and to a certain extent known group validity of the Dutch MORi and MADM measures in pregnant women.
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Toma de Decisiones , Parto Obstétrico/normas , Servicios de Salud Materna/normas , Parto/fisiología , Autonomía Personal , Calidad de la Atención de Salud , Adulto , Estudios Transversales , Femenino , Personal de Salud , Humanos , Madres , Países Bajos , Obstetricia , Embarazo , Mujeres Embarazadas , Psicometría , Reproducibilidad de los Resultados , Traducciones , Adulto JovenRESUMEN
Two types of cements were selected as the reference cement in the priority program 2005 of the German Research Foundation (DFG SPP 2005). A thorough characterization of CEM I 42.5 R has been made in a recent publication [1]. In this paper, the characterization data of the other reference cement CEM III/A 42.5â¯N are presented from the aspects of chemical and mineralogical compositions as well as physical and chemical properties. The characterization data of the slag, which is the second main constituent of this specific cement besides the clinker, are presented independently. For all data received, the mean values and the corresponding errors were calculated. The data shall be used for the ongoing research within the priority program. Also, researchers from outside this priority program can benefit from these data if the same materials are used.
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A thorough characterization of starting materials is the precondition for further research, especially for cement, which contains various phases and presents quite a complex material for fundamental scientific investigation. In the paper at hand, the characterization data of the reference cement CEM I 42.5 R used within the priority program 2005 of the German Research Foundation (DFG SPP 2005) are presented from the aspects of chemical and mineralogical compositions as well as physical and chemical properties. The data were collected based on tests conducted by nine research groups involved in this cooperative program. For all data received, the mean values and the corresponding errors were calculated. The results shall be used for the ongoing research within the priority program.
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BACKGROUND: Long-term non-invasive positive pressure ventilation (NIPPV) might improve the outcomes of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease (COPD) with chronic respiratory failure. A study was undertaken to investigate whether nocturnal NIPPV in addition to pulmonary rehabilitation improves health-related quality of life, functional status and gas exchange compared with pulmonary rehabilitation alone in patients with COPD with chronic hypercapnic respiratory failure. METHODS: 72 patients with COPD were randomly assigned to nocturnal NIPPV in addition to rehabilitation (n = 37) or rehabilitation alone (n = 35). Outcome measures were assessed before and after the 3-month intervention period. RESULTS: The Chronic Respiratory Questionnaire total score improved 15.1 points with NIPPV + rehabilitation compared with 8.7 points with rehabilitation alone. The difference of 7.5 points was not significant (p = 0.08). However, compared with rehabilitation alone, the difference in the fatigue domain was greater with NIPPV + rehabilitation (mean difference 3.3 points, p<0.01), as was the improvement in the Maugeri Respiratory Failure questionnaire total score (mean difference -10%, p<0.03) and its cognition domain (mean difference -22%, p<0.01). Furthermore, the addition of NIPPV improved daytime arterial carbon dioxide pressure (mean difference -0.3 kPa; p<0.01) and daily step count (mean difference 1269 steps/day, p<0.01). This was accompanied by an increased daytime minute ventilation (mean difference 1.4 l; p<0.001). CONCLUSION: Non-invasive ventilation augments the benefits of pulmonary rehabilitation in patients with COPD with chronic hypercapnic respiratory failure as it improves several measures of health-related quality of life, functional status and gas exchange.
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Hipercapnia/rehabilitación , Respiración con Presión Positiva/métodos , Enfermedad Pulmonar Obstructiva Crónica/rehabilitación , Adulto , Anciano , Dióxido de Carbono/sangre , Disnea/etiología , Tolerancia al Ejercicio/fisiología , Femenino , Volumen Espiratorio Forzado/fisiología , Humanos , Hipercapnia/sangre , Hipercapnia/fisiopatología , Masculino , Persona de Mediana Edad , Trastornos del Humor/etiología , Enfermedad Pulmonar Obstructiva Crónica/sangre , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Calidad de Vida , Capacidad Vital/fisiologíaRESUMEN
BACKGROUND: The vast majority of children will undergo their first exposure to common allergenic foods at home. However, the first exposure may lead to clinical reactions. It has been proposed to introduce allergenic foods gradually into the diets of children at risk for food allergy, but no practical dietary advice has been devised. OBJECTIVE: The aim of this study was to devise safe introduction schedules for common allergenic foods for use at home, based on the challenge doses as administered in double-blind, placebo-controlled food challenge (DBPCFCs) in children who were never exposed previously to these foods. METHODS: Seventy-two DBPCFCs were performed in 63 children as a first known exposure. The incrementing challenge doses were converted into equivalent portions of these foods in their usual household form and incorporated in introduction schedules. The feasibility of the introduction scales was tested in parents of the children attending our clinic. RESULTS: Based on the results of the positive challenges (37) in which severe reactions did not occur, detailed introduction schedules and a reference photograph of the required increasing amounts of food were devised for use at home. Feasibility testing showed that, when using these introduction schedules, parents portioned the initial doses significantly lower than without detailed instructions. CONCLUSIONS: The introduction schedules and reference photograph provide information for parents to introduce the required amounts of allergenic foods in initial low doses at home. This is expected to improve the safety of this procedure.
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Dieta/normas , Proteínas en la Dieta/administración & dosificación , Hipersensibilidad a los Alimentos/prevención & control , Administración Oral , Adolescente , Alérgenos/inmunología , Distribución de Chi-Cuadrado , Niño , Preescolar , Proteínas en la Dieta/efectos adversos , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Estudios de Factibilidad , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Padres/educación , Pruebas CutáneasRESUMEN
Although primary cilia are increasingly recognized to play sensory roles in several cellular systems, their role in vascular smooth muscle cells (VSMCs) has not been defined. We examined in situ position/orientation of primary cilia and ciliary proteins in VSMCs and tested the hypothesis that primary cilia of VSMCs exert sensory functions. By immunofluorescence and electron microscopic imaging, primary cilia of VSMCs were positioned with their long axis aligned at 58.3 degrees angle in relation to the cross-sectional plane of the artery, projecting into the extracellular matrix (ECM). Polycystin-1, polycystin-2 and alpha 3- and beta1-integrins are present in cilia. In scratch wound experiments, the majority of cilia were repositioned to the cell-wound interface. Such repositioning was largely abolished by a beta1-integrin blocker. Moreover, compared to non-ciliated/deciliated cells, ciliated VSMCs showed more efficient migration in wound repair. Lastly, when directly stimulated with collagen (an ECM component and cognate ligand for alpha 3beta1-integrins) or induced ciliary deflection, VSMCs responded with a rise in [Ca(2+)](i) that is dependent on the presence of cilia. Taken together, primary cilia of VSMCs are preferentially oriented, possess proteins critical for cell-ECM interaction and mechanosensing and respond to ECM protein and mechanical stimulations. These observations suggest a role for primary cilia in mechanochemical sensing in vasculature.
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Cilios/patología , Cilios/fisiología , Músculo Liso Vascular/patología , Animales , Aorta , Cilios/química , Colágeno/farmacología , Integrina beta1/análisis , Mecanotransducción Celular , Ratones , Microscopía , Miocitos del Músculo Liso/patología , Cicatrización de HeridasRESUMEN
PURPOSE: The problem of complex healthcare to MS patients, together with the rising prevalence of MS and escalating costs, has caused healthcare policy makers to consider innovative approaches to controlling costs and improving the quality of care. An integrated care approach may provide a means for better coordination and delivery of care. The aim is to review recent integrated care initiatives and their significance for MS patients. METHOD: A literature search was conducted to trace relevant literature on integrated care for MS patients published between 1995 and 2003. RESULTS: Although integrated care appears to offer potential for eliminating fragmentation and discontinuity in healthcare for MS patients, there are few published studies which have evaluated its implementation with MS patients. CONCLUSIONS: Even though the potential advantages of integrated care are well known, the applicability of this approach for MS patients has still to be demonstrated.
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Prestación Integrada de Atención de Salud , Esclerosis Múltiple/rehabilitación , HumanosRESUMEN
Iodine-123 phenylpentadecanoic acid (IPPA) is a synthetic long chain fatty acid with myocardial kinetics similar to palmitate. Two hypotheses were tested in this study. The first hypothesis was that IPPA imaging with single photon emission computed tomography (SPECT) is useful in the identification of patients with coronary artery disease. Fourteen normal volunteers (aged 27 +/- 2 years) and 33 patients (aged 54 +/- 11 years) with stable symptomatic coronary artery disease and at least one major coronary artery with luminal diameter narrowing greater than or equal to 70% were studied with symptom-limited maximal exercise testing. The IPPA (6 to 8 mCi) was injected 1 min before the termination of exercise, and tomographic imaging was performed beginning at 9 min and repeated at 40 min after the injection of IPPA. Nine of the normal volunteers and 13 of the patients had a second examination performed at rest on another day. Using the limits of normal as 2 SD from the normal mean values, 27 of the 33 patients with coronary artery disease demonstrated abnormalities in either the initial distribution or the clearance of IPPA, or both. Nineteen of the 33 patients had a maximal variation of activity distribution of greater than or equal to 25% on the 9 min IPPA images. Twenty-two of the 33 patients had a maximal variation in IPPA washout greater than 17% and 17 had a washout rate less than or equal to 2%. There was good agreement between the location of significant coronary artery stenoses and abnormalities in the initial distribution and clearance of IPPA. The second hypothesis tested was that IPPA imaging is as or more sensitive and, therefore, complementary to thallium-201 imaging in the identification of exercise-induced ischemia in patients. Twenty-five of the 33 patients underwent both thallium-201 and IPPA tomographic imaging after symptom-limited maximal exercise testing. The amount of exercise performed by each patient during both studies was similar. Twenty-one of the 25 patients had abnormal IPPA tomographic studies, whereas 18 had abnormal thallium-201 tomographic studies (p = NS). The results of this study suggest the following conclusions: 1) iodine-123 phenylpentadecanoic acid imaging using single photon emission computed tomography and exercise provides a sensitive and relatively noninvasive method for identifying abnormalities in myocardial metabolism associated with significant coronary artery stenoses, and 2) iodine-123 phenylpentadecanoic acid is at least as sensitive as thallium-201 for this purpose using tomographic imaging and exercise testing.
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Enfermedad Coronaria/diagnóstico por imagen , Yodobencenos , Miocardio/metabolismo , Radioisótopos de Talio , Tomografía Computarizada de Emisión , Adulto , Anciano , Enfermedad Coronaria/metabolismo , Enfermedad Coronaria/fisiopatología , Electrocardiografía , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Consumo de OxígenoRESUMEN
The use of planar radionuclide ventriculography to evaluate global and segmental ventricular function is limited by the superimposition of structures in some projections and the gross segmental resolution of the planar technique. Preliminary reports have suggested the feasibility of tomographic gated radionuclide ventriculography with rotating detector systems. This study tested the hypotheses that 1) tomographic radionuclide ventriculography detects segmental dysfunction at rest not identified with multiview planar studies and single plane contrast ventriculography, and 2) ventricular volumes and ejection fraction calculated from these studies provide data similar to those obtained with angiography and planar radionuclide ventriculography. Gated blood pool tomograms were acquired over 180 degrees at 15 frames per cardiac cycle during the initial 90% of the cardiac cycle. Compared with the multiview planar technique tomographic ventriculography showed an increased sensitivity for detecting left ventricular segments with significant coronary artery stenosis (97 versus 74%, p less than 0.025) without any loss in specificity. Compared with both planar radionuclide and contrast ventriculography, tomographic radionuclide ventriculography also detected more noninfarcted left ventricular segments supplied by stenosed coronary arteries (81 versus 39 and 32%, respectively, p less than 0.01). Tomographic radionuclide ventriculographic measurements of left ventricular volumes and ejection fraction showed close correlations with angiographic and planar radionuclide determinations. Gated blood pool tomography is a sensitive method for the evaluation of segmental wall motion and an accurate method for the measurement of global left ventricular volumes and ejection fraction.
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Volumen Cardíaco , Enfermedad Coronaria/fisiopatología , Contracción Miocárdica , Tomografía Computarizada de Emisión , Adulto , Anciano , Arteriopatías Oclusivas/diagnóstico por imagen , Arteriopatías Oclusivas/fisiopatología , Cateterismo Cardíaco , Enfermedad Coronaria/diagnóstico por imagen , Vasos Coronarios/diagnóstico por imagen , Eritrocitos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pertecnetato de Sodio Tc 99m , Volumen Sistólico , Tomografía Computarizada de Emisión/métodosRESUMEN
Tartrate-resistant acid phosphatase (TRACP) is produced by macrophages and other cells of the monohistiocytic lineage. In particular, osteoclasts are characterized for a high expression of this enzyme. Yet, several data suggest that other bone cell types, such as osteocytes and osteoblasts, may also express activity of this enzyme. This is particularly obvious at sites were osteoclasts resorb bone, suggesting that osteoclasts (or their precursors) somehow induce TRACP activity in osteoblasts. In the present study, we investigated this by culturing human osteoblast-like cells with and without conditioned medium (MCM) from human blood monocytes (as a source of osteoclast precursors). High levels of TRACP activity were found in osteoblast-like cells cultured with MCM. Depletion of TRACP from this medium resulted in the absence of its activity in osteoblast-like cells, thus suggesting that the TRACP activity in these cells was the result of endocytosed TRACP that was released by the monocytes in the MCM. Osteoblast-like cells cultured in control (non-conditioned) medium contained very low levels of TRACP-like activity. However, the cells expressed TRACP mRNA and incubation of extracts of these cells with active cathepsin B did induce activity of a TRACP-like enzyme. Inhibition of the activity of cysteine proteinases in general and of cathepsin B in particular, completely blocked TRACP activity of the osteoblast-like cells. This TRACP-like enzyme but not the alleged endocytosed fraction of TRACP was inhibited by fluoride, suggesting that the fractions may be different isoenzymes. Our data seem to indicate that osteoblast-like cells may contain two different fractions of TRACP, one that is released by monocytes and subsequently endocytosed by osteoblast-like cells and a second endogenous fraction that is present in an inactive proform. We hypothesize that the capacity of osteoblast-like cells to endocytose TRACP is important for the removal of this enzyme during or following the bone resorptive activity of the osteoclast.
Asunto(s)
Fosfatasa Ácida/metabolismo , Endocitosis/fisiología , Expresión Génica/genética , Isoenzimas/metabolismo , Osteoblastos/enzimología , Fosfatasa Ácida/efectos de los fármacos , Fosfatasa Ácida/genética , Fosfatasa Alcalina/genética , Fosfatasa Alcalina/metabolismo , Resorción Ósea/metabolismo , Catepsina B/antagonistas & inhibidores , Catepsina B/metabolismo , Catepsina B/farmacología , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/fisiología , Células Cultivadas , Técnicas de Cocultivo , Medios de Cultivo/farmacología , Medios de Cultivo Condicionados/farmacología , Inhibidores de Cisteína Proteinasa/farmacología , Vesículas Citoplasmáticas/química , Dipéptidos/farmacología , Activación Enzimática , Humanos , Isoenzimas/efectos de los fármacos , Isoenzimas/genética , Modelos Biológicos , Monocitos/citología , Monocitos/metabolismo , Osteoblastos/citología , Osteoblastos/metabolismo , Péptido Hidrolasas/metabolismo , Inhibidores de Proteasas/farmacología , Fluoruro de Sodio/farmacología , Fosfatasa Ácida TartratorresistenteRESUMEN
Staff and client attitudes toward heroin users and toward maintenance and abstient clients were assessed in 1970 and again in 1973. On each occasion there was striking agreement between the ratings made by staff and client groups. Abstinent clients were rated by all groups as significantly more effective and more responsible than either maintance clients or heroin users; maintenance clients were rated as more conservative, self-conscious, and self-effacing than were the other groups. While heroin users and abstinent clients were characterized similarly in the two rating periods, raters in the 1973 survey viewed methadone hydrochloride clients as more passive and less inclined to undertake adult responsibilities than was true of raters in the 1970 survey.
Asunto(s)
Actitud del Personal de Salud , Actitud , Metadona/uso terapéutico , Trastornos Relacionados con Sustancias/terapia , Actuación (Psicología) , Factores de Edad , Agresión , District of Columbia , Humanos , Autoevaluación (Psicología) , Ajuste Social , Predominio Social , Percepción Social , Encuestas y Cuestionarios , Factores de TiempoRESUMEN
In this study we investigated the role of bone lining cells in the coordination of bone resorption and formation. Ultrastructural analysis of mouse long bones and calvariae revealed that bone lining cells enwrap and subsequently digest collagen fibrils protruding from Howship's lacunae that are left by osteoclasts. By using selective proteinase inhibitors we show that this digestion depends on matrix metalloproteinases and, to some extent, on serine proteinases. Autoradiography revealed that after the bone lining cells have finished cleaning, they deposit a thin layer of a collagenous matrix along the Howship's lacuna, in close association with an osteopontin-rich cement line. Collagenous matrix deposition was detected only in completely cleaned pits. In bone from pycnodysostotic patients and cathepsin K-deficient mice, conditions in which osteoclastic bone matrix digestion is greatly inhibited, bone matrix leftovers proved to be degraded by bone lining cells, thus indicating that the bone lining cell "rescues" bone remodeling in these anomalies. We conclude that removal of bone collagen left by osteoclasts in Howship's lacunae is an obligatory step in the link between bone resorption and formation, and that bone lining cells and matrix metalloproteinases are essential in this process.