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Autopsy of a failed trial part 2: Outcomes, challenges, and lessons learnt from the DAISIES trial. EUROPEAN EATING DISORDERS REVIEW 2024; 32:476-489. [PMID: 38109218 DOI: 10.1002/erv.3058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 11/03/2023] [Accepted: 11/23/2023] [Indexed: 12/20/2023]
Abstract
OBJECTIVE The relative merits of inpatient or day-treatment for adults with anorexia nervosa (AN) are unknown. The DAISIES trial aimed to establish the non-inferiority of a stepped-care day patient treatment (DPT) approach versus inpatient treatment as usual (IP-TAU) for improving body mass index (BMI) at 12 months in adults with AN. The trial was terminated due to poor recruitment. This paper presents outcomes and investigates the reasons behind the trial's failure. METHOD Fifteen patients with AN (of 53 approached) participated and were followed-up to 6 or 12 months. Summary statistics were calculated due to low sample size, and qualitative data concerning treatment experiences were analysed using thematic analysis. RESULTS At baseline, participants in both trial arms rated stepped-care DPT as more acceptable. At 12 months, participants' BMIs had increased in both trial arms. Qualitative analysis highlighted valued and challenging aspects of care across settings. Only 6/12 sites opened for recruitment. Among patients approached, the most common reason for declining participation was their treatment preference (n = 12/38). CONCLUSIONS No conclusions can be drawn concerning the effectiveness of IP-TAU and stepped-care DPT, but the latter was perceived more positively. Patient-related, service-related and systemic factors (COVID-19) contributed to the trial's failure. Lessons learnt can inform future studies.
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Secreted frizzled related-protein 2 (Sfrp2) deficiency decreases adult skeletal stem cell function in mice. Bone Res 2021; 9:49. [PMID: 34857734 PMCID: PMC8639730 DOI: 10.1038/s41413-021-00169-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/21/2021] [Accepted: 06/27/2021] [Indexed: 12/18/2022] Open
Abstract
In a previous transcriptomic study of human bone marrow stromal cells (BMSCs, also known as bone marrow-derived "mesenchymal stem cells"), SFRP2 was highly over-represented in a subset of multipotent BMSCs (skeletal stem cells, SSCs), which recreate a bone/marrow organ in an in vivo ectopic bone formation assay. SFRPs modulate WNT signaling, which is essential to maintain skeletal homeostasis, but the specific role of SFRP2 in BMSCs/SSCs is unclear. Here, we evaluated Sfrp2 deficiency on BMSC/SSC function in models of skeletal organogenesis and regeneration. The skeleton of Sfrp2-deficient (KO) mice is overtly normal; but their BMSCs/SSCs exhibit reduced colony-forming efficiency, reflecting low SSC self-renewal/abundancy. Sfrp2 KO BMSCs/SSCs formed less trabecular bone than those from WT littermates in the ectopic bone formation assay. Moreover, regeneration of a cortical drilled hole defect was dramatically impaired in Sfrp2 KO mice. Sfrp2-deficient BMSCs/SSCs exhibited poor in vitro osteogenic differentiation as measured by Runx2 and Osterix expression and calcium accumulation. Interestingly, activation of the Wnt co-receptor, Lrp6, and expression of Wnt target genes, Axin2, C-myc and Cyclin D1, were reduced in Sfrp2-deficient BMSCs/SSCs. Addition of recombinant Sfrp2 restored most of these activities, suggesting that Sfrp2 acts as a Wnt agonist. We demonstrate that Sfrp2 plays a role in self-renewal of SSCs and in the recruitment and differentiation of adult SSCs during bone healing. SFRP2 is also a useful marker of BMSC/SSC multipotency, and a factor to potentially improve the quality of ex vivo expanded BMSC/SSC products.
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A Factor Analytic Model of Drug-Related Behavior in Adolescence and Its Impact on Arrests at Multiple Stages of the Life Course. JOURNAL OF QUANTITATIVE CRIMINOLOGY 2017; 33:131-155. [PMID: 28435183 PMCID: PMC5400364 DOI: 10.1007/s10940-016-9286-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
OBJECTIVES Recognizing the inherent variability of drug-related behaviors, this study develops an empirically-driven and holistic model of drug-related behavior during adolescence using factor analysis to simultaneously model multiple drug behaviors. METHODS The factor analytic model uncovers latent dimensions of drug-related behaviors, rather than patterns of individuals. These latent dimensions are treated as empirical typologies which are then used to predict an individual's number of arrests accrued at multiple phases of the life course. The data are robust enough to simultaneously capture drug behavior measures typically considered in isolation in the literature, and to allow for behavior to change and evolve over the period of adolescence. RESULTS Results show that factor analysis is capable of developing highly descriptive patterns of drug offending, and that these patterns have great utility in predicting arrests. Results further demonstrate that while drug behavior patterns are predictive of arrests at the end of adolescence for both males and females, the impacts on arrests are longer lasting for females. CONCLUSIONS The various facets of drug behaviors have been a long-time concern of criminological research. However, the ability to model multiple behaviors simultaneously is often constrained by data that do not measure the constructs fully. Factor analysis is shown to be a useful technique for modeling adolescent drug involvement patterns in a way that accounts for the multitude and variability of possible behaviors, and in predicting future negative life outcomes, such as arrests.
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Measuring Brain Tissue Integrity during 4 Years Using Diffusion Tensor Imaging. AJNR Am J Neuroradiol 2016; 38:31-38. [PMID: 27659189 DOI: 10.3174/ajnr.a4946] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 07/26/2016] [Indexed: 01/22/2023]
Abstract
BACKGROUND AND PURPOSE DTI is an MR imaging measure of brain tissue integrity. Little is known regarding the long-term longitudinal evolution of lesional and nonlesional tissue DTI parameters in multiple sclerosis and the present study examines DTI evolution over 4 years. MATERIALS AND METHODS Twenty-one patients with multiple sclerosis were imaged for up to 48 months after starting natalizumab therapy. Gadolinium-enhancing lesions at baseline, chronic T2 lesions, and normal-appearing white matter were followed longitudinally. T2 lesions were subclassified as black holes and non-black holes. Within each ROI, the average values of DTI metrics were derived by using Analysis of Functional Neuro Images software. The longitudinal trend in DTI metrics was estimated by using a mixed-model regression analysis. RESULTS A significant increase was observed for axial diffusivity (P < .001) in gadolinium-enhancing lesions and chronic T2 lesions during 4 years. No significant change in radial diffusivity either in normal-appearing white matter or lesional tissue was observed. The evolution of axial diffusivity was different in gadolinium-enhancing lesions (P < .001) and chronic T2 lesions (P = .02) compared with normal-appearing white matter. CONCLUSIONS An increase in axial diffusion in both gadolinium-enhancing lesions and T2 lesions may relate to the complex evolution of chronically demyelinated brain tissue. Pathologic changes in normal-appearing white matter are likely more subtle than in lesional tissue and may explain the stability of these measures with DTI.
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On the Association Between Repeat Bully Victimizations and Carrying a Firearm: Evidence in a National Sample. INTERNATIONAL JOURNAL OF OFFENDER THERAPY AND COMPARATIVE CRIMINOLOGY 2016; 60:871-896. [PMID: 25733742 DOI: 10.1177/0306624x15573547] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Bullying is a significant public concern. The purpose of the present study is to investigate whether being repeatedly victimized by a bully during childhood and adolescence is associated with gun carrying in adolescence and adulthood. Using data from the National Longitudinal Survey of Youth 1997, we found that just over one fourth of the respondents reported carrying a gun at some point in their lifetime. Respondents experiencing repeat bully victimizations reported higher rates of gun carrying during the last 12 months and the last 30 days. No support was found for the association of repeat bully victimizations and carrying a gun to school. Individuals victimized during childhood (before the age of 12) and during adolescence were found to be at risk of carrying a gun later in the life course. Repeat bully victimizations should be considered a marker for gun-carrying behaviors in adolescence and adulthood.
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Narratives of HIV: measuring understanding of HIV and the law in HIV-positive patients. ACTA ACUST UNITED AC 2015; 42:30-5. [PMID: 25589092 DOI: 10.1136/jfprhc-2013-100789] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 11/27/2014] [Indexed: 11/04/2022]
Abstract
OBJECTIVE This study aimed to identify the understanding of people living with HIV and AIDS (PLWHA) regarding the application of the law around transmission of HIV in England and Wales. DESIGN A questionnaire was designed to prompt participants attending a large HIV department to discuss their understanding of the law with reference to HIV transmission. The design focused on qualitative analysis as there were insufficient data available to inform a metric reflecting quantitative data on PLWHA's understanding of the legal implications of transmission. METHODS The data were collected from PLWHA attending their HIV outpatient appointment to ensure relevance of population to the analysis. The answers were analysed using grounded theory and thematic analysis to identify key themes and theories for further testing. RESULTS Analysis demonstrated that understanding of legal obligations and outcomes of prosecutions was poor and patchy, with behavioural restrictions often overstated. There was a strong theme of ownership of responsibility amongst PLWHA, and of reference to principles of morality beyond legal restrictions. CONCLUSIONS PLWHA remain at risk of prosecution through poor understanding of the law. Clinical services and advocacy agencies should strive to increase understanding in order to enable PLWHA to comprehend the law and negotiate it successfully. This information should be shared as a process, not an isolated event.
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Like Parent Like Child? The Role of Delayed Childrearing in Breaking the Link Between Parent's Offending and Their Children's Antisocial Behavior. JUSTICE QUARTERLY : JQ 2015; 32:410-444. [PMID: 26392677 PMCID: PMC4573638 DOI: 10.1080/07418825.2013.771206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
This paper investigates the impact of parents' history of violent offending, their age at first birth, and the interaction of the two on their adolescent children's violent behavior. We employ intergenerational longitudinal data from the Rochester Youth Development Study to estimate parental trajectories of offending from their early adolescence through early adulthood. We show that the particular shape of the parents' propensity of offending over time can interact with their age at first birth to protect their children from delinquency. We investigate these relationships for children at 6 and 10 years of age. We find that for some groups delaying childrearing can insulate children from their parents' offending.
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Diffusion tensor imaging before, during and after progressive multifocal leukoencephalopathy. Eur J Neurol 2014; 21:e36-8. [PMID: 24628903 DOI: 10.1111/ene.12361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 12/17/2013] [Indexed: 12/01/2022]
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Directed differentiation of human induced pluripotent stem cells toward bone and cartilage: in vitro versus in vivo assays. Stem Cells Transl Med 2014; 3:867-78. [PMID: 24855277 DOI: 10.5966/sctm.2013-0154] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The ability to differentiate induced pluripotent stem cells (iPSCs) into committed skeletal progenitors could allow for an unlimited autologous supply of such cells for therapeutic uses; therefore, we attempted to create novel bone-forming cells from human iPSCs using lines from two distinct tissue sources and methods of differentiation that we previously devised for osteogenic differentiation of human embryonic stem cells, and as suggested by other publications. The resulting cells were assayed using in vitro methods, and the results were compared with those obtained from in vivo transplantation assays. Our results show that true bone was formed in vivo by derivatives of several iPSC lines, but that the successful cell lines and differentiation methodologies were not predicted by the results of the in vitro assays. In addition, bone was formed equally well from iPSCs originating from skin or bone marrow stromal cells (also known as bone marrow-derived mesenchymal stem cells), suggesting that the iPSCs did not retain a "memory" of their previous life. Furthermore, one of the iPSC-derived cell lines formed verifiable cartilage in vivo, which likewise was not predicted by in vitro assays.
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Sensorimotor cortex gamma-aminobutyric acid concentration correlates with impaired performance in patients with MS. AJNR Am J Neuroradiol 2013; 34:1733-9. [PMID: 23493890 DOI: 10.3174/ajnr.a3483] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Abnormalities in GABA concentration [GABA] have been associated with several neuropsychiatric disorders, and research has suggested that GABA may play a role in sensorimotor cortex function. We sought to determine whether identifying a change in [GABA] within the sensorimotor cortex of patients with MS has any effect on motor function and would provide information about the adaptive/compensatory mechanisms involved in the attempt to maintain motor function during disease progression. MATERIALS AND METHODS In 19 healthy controls and 30 patients with MS, we assessed task performance with the MS Functional Composite scale and its components (T25FW test, 9HPT, and PASAT). With in vivo MR spectroscopy, we measured [GABA] in the sensorimotor cortex and determined correlations between [GABA] and task performance. We also assessed the association between [GABA] and cortical activation volume after a bilateral finger-tapping task. RESULTS [GABA] was inversely correlated with 9HPT scores in patients with MS, indicating a worsening of performance with increased [GABA]. No significant correlation was observed between [GABA] and T25FW or PASAT scores. [GABA] was directly correlated with primary motor cortex activation volume after the finger-tapping task in patients with MS. CONCLUSIONS These results suggest that cortical [GABA] may be a marker of function and reorganization/adaptation of cortical gray matter in MS.
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Sex differences in resting-state functional connectivity in multiple sclerosis. AJNR Am J Neuroradiol 2013; 34:2304-11. [PMID: 23811974 DOI: 10.3174/ajnr.a3630] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND AND PURPOSE Multiple studies have demonstrated evidence of sex differences in patients with MS, including differences in disease progression, cognitive decline, and biologic markers. This study used functional connectivity MRI to investigate sex differences in the strength of functional connectivity of the default mode network in patients with MS and healthy control subjects. MATERIALS AND METHODS A total of 16 men and 16 women with MS and 32 age- and sex-matched healthy control subjects underwent a whole-brain resting-state functional connectivity MRI scan. A group-based seed in the posterior cingulate was used to create whole-brain correlation maps. A 2 × 2 ANOVA was used to assess whether disease status and sex affected the strength of connectivity to the posterior cingulate. RESULTS Patients with MS showed significantly stronger connectivity from the posterior cingulate to the bilateral medial frontal gyri, the left ventral anterior cingulate, the right putamen, and the left middle temporal gyrus (P < .0005). In the left dorsal lateral prefrontal cortex, female patients showed significantly stronger connectivity to the posterior cingulate cortex compared with female control subjects (P = 3 × 10(4)), and male control subjects showed stronger posterior cingulate cortex-left dorsal lateral prefrontal cortex connectivity in comparison to female control subjects (P = .002). Male patients showed significantly weaker connectivity to the caudate compared with female patients (P = .004). CONCLUSIONS Disease status and sex interact to produce differences in the strength of functional connectivity from the posterior cingulate to the caudate and the left dorsal lateral prefrontal cortex.
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Application of a computerized language lateralization index from FMRI by a group of clinical neuroradiologists. AJNR Am J Neuroradiol 2013; 34:564-9. [PMID: 22976237 PMCID: PMC7964916 DOI: 10.3174/ajnr.a3271] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 06/16/2012] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Deriving accurate language lateralization from fMRI studies in the clinical context can be difficult, with 10%-20% incorrect conclusions. Most interpretations are qualitative, performed by neuroimaging experts. Quantitative lateralization has been widely described but with little implementation in the clinical setting and is disadvantaged by the use of arbitrary threshold techniques. We investigated the application and utility of a nonthreshold CLI, in a clinical setting, as applied by a group of practicing neuroradiologists. MATERIALS AND METHODS Twenty-two patients with known language lateralization (11 left and 11 nonleft dominant) had their images reviewed by 8 neuroradiologists in 2 settings, all randomized, once by using a CLI and once without using a CLI. For each review, neuroradiologists recorded their impressions of lateralization for each language sequence, the overall lateralization conclusion, their impression of scan quality and noise, and the subjective confidence in their conclusion. RESULTS The inter-rater κ for lateralization was 0.64, which increased to 0.70 with the use of CLI. The group accuracy of overall lateralization was 78%, which increased to 81% with the use of a CLI. Using a CLI removed 2 instances of significant errors, with a neuroradiologist's impression of left lateralization in a patient with known right lateralization. Using a CLI had no effect on examinations with conclusions formed with either high confidence or no confidence. CONCLUSIONS Although the overall clinical benefit of a CLI is modest, the most significant impact is to reduce the most harmful misclassification errors, particularly in fMRI examinations that are suboptimal.
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Are Risky Youth Less Protectable As They Age? The Dynamics of Protection During Adolescence and Young Adulthood. JUSTICE QUARTERLY : JQ 2013; 30:501-528. [PMID: 24363492 DOI: 10.1080/07418825.2011.606226] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Research on recidivism in criminal justice and desistance in criminology are not integrated. Yet, both fields seem to be moving towards models that look at how positive elements in a person's environment can impact a person's behavior, conditional on different levels of risk. This study builds on this observation by applying interactional theory and the concept of Risk-Needs-Responsivity to theorize that both Needs and Responsivity will change over time in predictable ways. We then use a novel empirical approach with the Rochester Youth Development Study to show that even in late adolescence, individuals who are at risk for violence can be protected from future violence and risky behavior like gun carrying with positive events in their environment and personal life. In young adulthood, fewer people are still at risk for violence, and those who are at risk are harder to protect from future violence and gun carrying.
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Are Risky Youth Less Protectable As They Age? The Dynamics of Protection During Adolescence and Young Adulthood. JUSTICE QUARTERLY : JQ 2013; 30:10.1080/07418825.2011.592507. [PMID: 24363492 PMCID: PMC3867295 DOI: 10.1080/07418825.2011.592507] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Research on recidivism in criminal justice and desistance in criminology are not integrated. Yet, both fields seem to be moving towards models that look at how positive elements in a person's environment can impact a person's behavior, conditional on different levels of risk. This study builds on this observation by applying interactional theory and the concept of Risk-Needs-Responsivity to theorize that both Needs and Responsivity will change over time in predictable ways. We then use a novel empirical approach with the Rochester Youth Development Study to show that even in late adolescence, individuals who are at risk for violence can be protected from future violence and risky behavior like gun carrying with positive events in their environment and personal life. In young adulthood, fewer people are still at risk for violence, and those who are at risk are harder to protect from future violence and gun carrying.
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Assessing the Impact of Drug Use and Drug Selling on Violent Offending in a Panel of Delinquent Youth. JOURNAL OF DRUG ISSUES 2012; 42:298-316. [PMID: 26889079 PMCID: PMC4754201 DOI: 10.1177/0022042612456017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Despite a vast number of empirical studies arguing for or against a causal relationship between illegal drug use and selling and violent behavior, the debate continues. In part this is due to methodological weaknesses of previous research. Using data from the Rochester Youth Development Study, the current study seeks to improve on prior research designs to allow for a more precise examination of the mechanisms that lead from an individual's drug use (chiefly, marijuana use in the current sample) and drug selling to violent action. Results will allow for greater confidence in making causal inference regarding a long-standing concern in the discipline.
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P42 An audit of Neisseria gonorrhoeaedetection methods in a district general hospital genitourinary medicine service: Abstract P42 Table 1. Br J Vener Dis 2012. [DOI: 10.1136/sextrans-2012-050601c.42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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P178 Is punishment and criminalisation of HIV transmission justified? Br J Vener Dis 2012. [DOI: 10.1136/sextrans-2012-050601c.178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Rough endoplasmic reticulum trafficking errors by different classes of mutant dentin sialophosphoprotein (DSPP) cause dominant negative effects in both dentinogenesis imperfecta and dentin dysplasia by entrapping normal DSPP. J Bone Miner Res 2012; 27:1309-21. [PMID: 22392858 PMCID: PMC3390460 DOI: 10.1002/jbmr.1573] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Families with nonsyndromic dentinogenesis imperfecta (DGI) and the milder, dentin dysplasia (DD), have mutations in one allele of the dentin sialophosphoprotein (DSPP) gene. Because loss of a single Dspp allele in mice (and likely, humans) causes no dental phenotype, the mechanism(s) underling the dominant negative effects were investigated. DSPP mutations occur in three classes. (The first class, the mid-leader missense mutation, Y6D, was not investigated in this report.) All other 5′ mutations of DSPP result in changes/loss in the first three amino acids (isoleucine-proline-valine [IPV]) of mature DSPP or, for the A15V missense mutation, some retention of the hydrophobic leader sequence. All of this second class of mutations caused mutant DSPP to be retained in the rough endoplasmic reticulum (rER) of transfected HEK293 cells. Trafficking out of the rER by coexpressed normal DSPP was reduced in a dose-responsive manner, probably due to formation of Ca2+-dependent complexes with the retained mutant DSPP. IPV-like sequences begin many secreted Ca2+-binding proteins, and changing the third amino acid to the charged aspartate (D) in three other acidic proteins also caused increased rER accumulation. Both the leader-retaining A15V and the long string of hydrophobic amino acids resulting from all known frameshift mutations within the 3′-encoded Ca2+-binding repeat domain (third class of mutations) caused retention by association of the mutant proteins with rER membranes. More 5′ frameshift mutations result in longer mutant hydrophobic domains, but the milder phenotype, DD, probably due to lower effectiveness of the remaining, shorter Ca2+-binding domain in capturing normal DSPP protein within the rER. This study presents evidence of a shared underlying mechanism of capturing of normal DSPP by two different classes of DSPP mutations and offers an explanation for the mild (DD-II) versus severe (DGI-II and III) nonsyndromic dentin phenotypes. Evidence is also presented that many acidic, Ca2+-binding proteins may use the same IPV-like receptor/pathway for exiting the rER.
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Effect of a prescan patient-radiologist encounter on functional MR image quality. AJNR Am J Neuroradiol 2011; 32:210-5. [PMID: 20705700 DOI: 10.3174/ajnr.a2220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE A substantial number of clinical fMRI examinations inadequately assess language localization or lateralization, usually due to patient movement and suboptimal participation. We hypothesized that a prescan interview of the patient by the radiologist would reduce the fraction of nondiagnostic scans. MATERIALS AND METHODS A single noise score for each acquisition was produced from time-series data on the basis of a weighted sum of 22 factors. Scores were recorded as the following quartiles: 0-5 = excellent, 5-10 = adequate, 10-15= marginal, and >15 = unacceptable. This measure was evaluated for 202 consecutive fMRI patients: 96 without and 106 with a physician prescan interview. The data were analyzed to compute the fraction of all nondiagnostic sequences and entire studies and were compared between the 2 groups. Image-noise characteristics included the SDs of linear and angular displacements of the head and the number of time-series outliers caused by focal motion. RESULTS Of 999 sequences acquired, 539 had a prescan interview. The mean noise score significantly decreased for both individual sequence (from 7.9 to 6.3, P = <.001) and study-based (from 7.7 to 6.2, P = .05) methods. The fraction of sequences or studies scored as unacceptable decreased for sequence-based (from 15.2% to 10.9%, P = .04) and study-based (from 9.4% to 1.9%, P = .02) analyses. SDs of head motion decreased for linear (by 12%-14%, P < .01) and angular displacement (by 38%-48%, P < .001). The number of time-series spikes decreased by 10% (P = .004). CONCLUSIONS We report that a prescan physician-patient interview modestly but significantly reduces fMRI noise scores. These results support the newly added billable costs of professional intervention before fMRI scans.
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Abstract
The specific aims of this study were to quantify the effects of 12 weeks of resistance training, as well as a single session of resistance exercise on lipids and lipoproteins in obese, postmenopausal women. 21 obese, postmenopausal women, not on hormone replacement therapy (age=65.9 ± 0.5 yr; BMI=32.7 ± 0.8 kg/m(2)), were randomly assigned to control (n=12) and exercise (n=9) groups matched for age and BMI. For 12 weeks, 3 days/week, the exercise group performed 10 whole body resistance exercises (3 sets at 8-RM). Fasting (10 h) blood samples were collected immediately prior to and 24 h after the first and last exercise and control session. Serum was assayed for concentrations of total cholesterol, triglycerides, LDL-C, HDL-C, HDL 2-C, HDL 3-C, non-HDL-C and TC:HDL and LDL:HDL ratios. The exercise group exhibited a significant (P<0.01) improvement in muscular strength, but no change in BMI, body mass or body composition post-training. Total cholesterol, LDL-C and non-HDL-C were significantly (P<0.05) lower in the exercise compared to the control group following the 12 weeks of resistance training. Whole body resistance training provides obese, postmenopausal women a non-pharmacological approach for the reduction of lipid and lipoprotein-cholesterol concentrations.
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Abstract
BACKGROUND AND PURPOSE DTI is an MR imaging measure of brain tissue integrity and provides an attractive metric for use in neuroprotection clinical trials. The purpose of our study was to use DTI to evaluate the longitudinal changes in brain tissue integrity in a group of patients with MS. MATERIALS AND METHODS Twenty-one patients with MS starting natalizumab were imaged serially for 12 months. Gadolinium-enhancing lesions and 20 regions of interest from normal-appearing white and gray matter brain tissue were followed longitudinally. Average values within each region of interest were derived for FA, λ(∥), λ(⊥), and MD. New T1 black holes were identified at 12 months. Analysis was performed by using mixed-model regression analysis with slope (ie, DTI change per month) as the dependent variable. RESULTS During 1 year, FA increased in gadolinium-enhancing lesions but decreased in NABT (P < .0001 for both). Changes in FA within gadolinium-enhancing lesions were driven by decreased λ(⊥) (P < .001), and within NABT, by decreased λ(∥) (P < .0001). A higher λ(⊥) within gadolinium-enhancing lesions at baseline predicted conversion to T1 black holes at 12 months. MD was unchanged in both gadolinium-enhancing lesions and NABT. CONCLUSIONS We observed changes in DTI measures during 1 year in both gadolinium-enhancing lesions and NABT. The DTI results may represent possible remyelination within acute lesions and chronic axonal degeneration in NAWM. These results support the use of DTI as a measure of tissue integrity for studies of neuroprotective therapies.
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Dkk1 and Dkk2 regulate epicardial specification during mouse heart development. Int J Cardiol 2010; 150:186-92. [PMID: 20439124 DOI: 10.1016/j.ijcard.2010.04.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Accepted: 04/02/2010] [Indexed: 11/16/2022]
Abstract
BACKGROUND Dkk1 and Dkk2 interact with LRP5 and LRP6 to modulate canonical Wnt signaling during development, and are known to be expressed in the developing heart. However, a loss-of-function mutation in either gene by itself produces no discernable heart phenotype. METHODS Using standard husbandry techniques, Dkk1 null and Dkk2 null mouse lines were crossed to create double null embryos, which we examined using histological and immunohistochemical methods. RESULTS Double null embryos die perinatally, with a gross head phenotype reminiscent of Dkk1 null embryos. Upon examination of late stage hearts, we observe myocardial defects including ventricular septal defects. At earlier stages, double mutant hearts show myocardial and epicardial hyperplasia. Myocardial hypertrophy is associated with a moderate increase in cell proliferation, but epicardial hypercellularity is not. Rather, the field of proepicardial precursor cells near the liver shows a broadening of expression for the cardiac-specific gap junction protein Connexin 43. CONCLUSIONS Dkk1 and Dkk2 both inhibit Wnt signaling to regulate early myocardial proliferation and each can compensate for the loss of the other in that role. Wnt signaling regulates myocardial proliferation in both heart fields at early stages. Additionally, Wnt signaling is sufficient to increase proepicardial specification as measured by Connexin 43 expression, resulting in a hypercellular epicardium and perhaps contributing to later defects.
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Hybrid Odontogenic Tumor With Features of Ameloblastic Fibro-Odontoma, Calcifying Odontogenic Cyst, and Adenomatoid Odontogenic Tumor: A Case Report and Review of the Literature. J Oral Maxillofac Surg 2010; 68:470-4. [DOI: 10.1016/j.joms.2009.04.118] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Accepted: 04/23/2009] [Indexed: 10/19/2022]
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The LIM-domain binding protein Ldb1 is required for proper endocardial cushion formation during heart development in Mus musculus. Dev Biol 2008. [DOI: 10.1016/j.ydbio.2008.05.435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Spectral quality control in motion-corrupted single-voxel J-difference editing scans: an interleaved navigator approach. Magn Reson Med 2008; 58:808-12. [PMID: 17899594 DOI: 10.1002/mrm.21337] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Motion has an adverse effect on spectral quality and needs to be properly identified in MR spectroscopy (MRS) scans. Spectral subtraction-based techniques like J-difference editing are prone to be affected more by subject motion where motion can result in false peaks or inefficient subtraction of peaks. Introducing a water signal-based interleaved navigator scan in the MEGA point-resolved spectroscopy (MEGA-PRESS) sequence and acquiring data on a shot-by-shot basis, subject motion inside a scanner was tracked and motion-corrupted data were identified and excluded from the dataset. Performing a gamma-aminobutyric acid (GABA) editing scan at the occipital cortex, it was possible to retrieve a properly edited GABA spectrum from a dataset otherwise to be discarded due to motion. This study demonstrates the importance of independent motion assessment in J-difference editing.
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Hydrogen Bonding and Multiphonon Structure in Copper Pyrazine Coordination Polymers. Inorg Chem 2007; 46:8577-83. [PMID: 17845028 DOI: 10.1021/ic070122t] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a systematic investigation of the temperature-dependent infrared vibrational spectra of a family of chemically related coordination polymer magnets based upon bridging bifluoride (HF(2)-) and terminal fluoride (F-) ligands in copper pyrazine complexes including Cu(HF(2))(pyz)(2)BF(4), Cu(HF(2))(pyz)(2)ClO(4), and CuF(2)(H(2)O)(2)(pyz). We compare our results with several one- and two-dimensional prototype materials including Cu(pyz)(NO(3))(2) and Cu(pyz)(2)(ClO(4))(2). Unusual low-temperature hydrogen bonding, local structural transitions associated with stronger low-temperature hydrogen bonding, and striking multiphonon effects that derive from coupling of an infrared-active fundamental with strong Raman-active modes of the pyrazine building-block molecule are observed. On the basis of the spectroscopic evidence, these interactions are ubiquitous to this family of coordination polymers and may work to stabilize long-range magnetic ordering at low temperature. Similar interactions are likely to be present in other molecule-based magnets.
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Magnetothermal transport in the spin-1/2 chains of copper pyrazine dinitrate. PHYSICAL REVIEW LETTERS 2007; 98:107201. [PMID: 17358560 DOI: 10.1103/physrevlett.98.107201] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Indexed: 05/14/2023]
Abstract
We present experiments on the thermal transport in the spin-1/2 chain compound copper pyrazine dinitrate Cu(C4H4N2)(NO3)2. The heat conductivity shows a surprisingly strong dependence on the applied magnetic field B, characterized at low temperatures by two main features. The first one appearing at low B is a characteristic dip located at muBB approximately kBT, that may arise from umklapp scattering. The second one is a plateaulike feature in the quantum critical regime, muB|B - Bc| < kBT, where Bc is the saturation field at T=0. The latter feature clearly points towards a momentum and field-independent mean free path of the spin excitations, contrary to theoretical expectations.
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Abstract
An apical brush border is a characteristic of many mature epithelia. This dynamic structure consists of dense microvilli supported by F-actin bundles that protrude into the apical cytoplasm, where they are crosslinked by spectrin and myosin II to form the terminal web. Little is known about the terminal web, through which vesicles transit to and from the apical membrane. Analysis of mutations in beta(Heavy)-spectrin, the Drosophila brush border spectrin, reveals that this protein is necessary for the maintenance of Rab5 endosomes in the midgut. As a consequence, an apical H+ V-ATPase that is probably responsible for lumenal acidification is lost both from the brush border and Rab5 endosomes. Epistasis tests indicate that beta(Heavy)-spectrin is required during endocytosis after Dynamin and before Rab5-mediated endosome activities. These data are consistent with the location of spectrin in the terminal web, and suggest that this molecule is required for correct sorting decisions at the early endosome.
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Diffusion-weighted imaging of white matter abnormalities in patients with phenylketonuria. AJNR Am J Neuroradiol 2001; 22:1583-6. [PMID: 11559511 PMCID: PMC7974588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2000] [Accepted: 03/23/2001] [Indexed: 02/21/2023]
Abstract
Phenylketonuria (PKU) is an autosomal recessive disorder caused by a deficiency of the enzyme phenylalanine hydroxylase (EC 1.14.16.1). Affected patients develop elevated plasma and tissue levels of phenylalanine and its related ketoacids. Untreated patients usually exhibit severe mental retardation and poor motor function, with characteristic T2 white matter signal abnormalities on conventional MR images. In the present study, we performed diffusion-weighted imaging in three PKU patients. All three patients demonstrated significantly restricted diffusion in all white matter areas examined.
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Abstract
PURPOSE To evaluate potential sex differences in temporal lobe activation during the performance of a functional magnetic resonance (MR) imaging passive-listening paradigm. MATERIALS AND METHODS Twenty strongly right-handed volunteers (10 men, 10 women) underwent imaging with a 1.5-T machine by using a gradient-echo echo-planar sequence. The task consisted of passive listening to simple narrative text interleaved with same-narrative text played backward. Volumes of interest were drawn around anterior and posterior areas of activation in bilateral temporal lobes. The peak percentage of activation and the percentage of activated voxels at single-voxel significance levels of 10(-2), 10(-3), and 10(-4) within each volume of interest were measured. An asymmetry index A was then calculated for both anterior and posterior volumes of interest such that A = (L - R)/(L + R), where R is either the peak percentage activation or the percentage of activated voxels within the right volume of interest and L is either the peak percentage activation or the percentage of activated voxels within the left volume of interest. The asymmetry indexes were compared between men and women by using a standard t test. RESULTS Men showed a significantly higher degree of asymmetric activation than did women in both the anterior and posterior volumes of interest by using peak percentage activation and at all single-voxel significance levels. The degree of activation asymmetry was greater by using single-voxel significance measurements, compared with peak percentage activation measures. CONCLUSION Women demonstrate a higher degree of bilateral language representation in temporal lobe regions than do men during passive listening. These findings, combined with the variable results of prior functional MR imaging language studies of sex differences, suggest that they may be task specific.
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Approach to functional magnetic resonance imaging of language based on models of language organization. Neuroimaging Clin N Am 2001; 11:343-53, x. [PMID: 11489743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Functional MR imaging (fMRI) has been a useful tool in the evaluation of language both in normal individuals and patient populations. The purpose of this article is to use various models of language as a framework to review fMRI studies. Specifically, fMRI language studies are subdivided into the following categories: word generation or fluency, passive listening, orthography, phonology, semantics, and syntax.
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Abstract
PURPOSE The Health Care Financing Administration (HCFA) regards billing for radiologic examinations without an appropriate indication as unlawful, and both the referring physician and the radiologist are liable. HCFA regulations are interpreted as requiring that all requisitions for radiologic examinations include a current diagnosis and appropriate indication for the study. The purpose of this investigation was to determine the rates at which requisitions currently meet these criteria and to assess the effectiveness of a simple intervention designed to improve them. MATERIALS AND METHODS One hundred fifty consecutive chest radiography requisitions were examined to determine the rate at which current diagnoses and appropriate indications were present. An intervention was then implemented that included a month-long effort to inform referring physicians and radiologists of HCFA regulations, followed by a 1-week period during which requested examinations were not performed unless accompanied by a clinical diagnosis and appropriate indication. Another 150 consecutive chest radiography requisitions were then assessed to determine the effect of the intervention. A 3-month follow-up sample of a third set of 150 consecutive requisitions was then obtained. RESULTS The intervention produced a 69% decrease in the rate at which current diagnoses were missing from requisitions, and a 61% decrease in the corresponding rate for appropriate indications. Both results are significant with chi2 analysis at the P = .001 level. After 3 months with no additional intervention, rates decayed back toward baseline, with only a 35% remaining decrease for current diagnosis and an 18% decrease for appropriate indication. CONCLUSION The intervention performed in this study significantly reduces the rate of noncompliance with HCFA regulations. However, this improvement decays over time if it is not reinforced.
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Abstract
A large east Texas family with autosomal dominant inheritance of a novel bleeding disorder has been identified. The disorder is characterized clinically by easy bruising, life-threatening bleeding with trauma or surgery, and menorrhagia in affected women. Laboratory studies demonstrated prolongation of the prothrombin time and activated partial thromboplastin time in affected individuals. Paradoxically, assays of known coagulation factors are all within normal limits. To determine the molecular basis of this disease, a candidate gene linkage analysis in this kindred was done. Initially it was hypothesized that the cause of the disease in this family could be an antithrombin III (AT3) mutation that resulted in a constitutively active AT3 in the absence of heparin binding. Linkage studies using DNA from the family and an intragenic polymorphic marker within the AT3 gene showed that the disease mapped to this locus. The coding region and intron/exon junctions of AT3 were sequenced using the proband's DNA, but this analysis failed to identify a mutation. Additional family members were recruited for the study, and 16 polymorphic markers around the AT3 gene were analyzed. Using 2 recombinants, the critical interval for the defective gene was narrowed to approximately 1.5 Mb, centromeric to AT3. The factor V (FV) gene was mapped into the disease interval and sequenced; there were no mutations found. Elucidation of the genetic defect causing the bleeding disorder in this family may reveal a novel protein involved in the coagulation cascade.
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Adherence to care plan in women with abnormal Papanicolaou smears: a review of barriers and interventions. THE JOURNAL OF THE AMERICAN BOARD OF FAMILY PRACTICE 2001; 14:123-30. [PMID: 11314919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
BACKGROUND Cancer of the cervix is preventable. According to the Surveillance, Epidemiology, and End Results (SEER) Program, invasive cervical cancer incidence is 9.0 and cancer mortality rate is 2.8 per 100,000 persons. Effective prevention includes appropriate use of Papanicolaou smears and adherence to a care plan by the patient. This review will examine the extent of nonadherence, negative outcomes, barriers, and interventions for improved adherence to care. METHODS Computer searches in MEDLINE for English language articles were conducted from 1968 to 1999 using the key words "colposcopy," "abnormal Papanicolaou smear," "patient compliance," "adherence to care," and "follow-up." RESULTS Although there is 10% to 40% nonadherence in the studies reviewed, the definition of nonadherence is not standard. Considerable morbidity from cervical cancer was described among nonadherent women. The most common barriers to follow-up were lack of understanding of the purpose of colposcopy, fear of cancer, forgetting appointments, and lack of time, money, or childcare. Emotional consequences of abnormal Papanicolaou smears had considerable impact on follow-up visits. Focused intervention strategies targeted to the study population were most effective in improving adherence. CONCLUSIONS Nonadherence results from the interplay of emotional, logistic, cultural, or socioeconomic factors. Among the most effective strategies to improve adherence are personalized reminders to patients by their primary physicians and case management dictated by the size, structure, and style of the practice.
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Abstract
Cross-correlation of low-frequency temporal fluctuations (<0.08 Hz) was used to correlate widely separated anatomic regions during continuous performance of a spatial working memory task. The regions of highest correlation to right-hemisphere dorsolateral prefrontal cortex correspond to the regions of largest baseline signal change in a conventional block-style functional MRI paradigm. Additionally, it is shown that the correlations between elements of the functional network increase during performance of a task that activates the network when compared to a task that does not directly stimulate the functionally connected network.
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Abstract
Multisection computed tomography (CT) was introduced in 1992 with the advent of dual-section-capable scanners and was improved in 1998 following the development of quad-section technology. With a recent increase in gantry speed from one to two revolutions per second, multisection CT scanners are now up to eight times faster than conventional single-section helical CT scanners. The benefits of quad-section CT relative to single-section helical CT are considerable. They include improved temporal resolution, improved spatial resolution in the z axis, increased concentration of intravascular contrast material, decreased image noise, efficient x-ray tube use, and longer anatomic coverage. These factors substantially increase the diagnostic accuracy of the examination. The multisection CT technique has enabled faster and superior evaluation of patients across a wide spectrum of clinical indications. These include isotropic viewing, musculoskeletal applications, use of multiplanar reformation in special situations, CT myelography, long coverage and multiphase studies, CT angiography, cardiac scoring, evaluation of brain perfusion, imaging of large patients, evaluation of acute chest pain or dyspnea, virtual endoscopy, and thin-section scanning with retrospective image fusing. Multisection CT is superior to single-section helical CT for nearly all clinical applications.
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Postexercise rehydration: effect of Na(+) and volume on restoration of fluid spaces and cardiovascular function. J Appl Physiol (1985) 2000; 89:1302-9. [PMID: 11007562 DOI: 10.1152/jappl.2000.89.4.1302] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Our purpose was to study the interaction between Na(+) content and fluid volume on rehydration (RH) and restoration of fluid spaces and cardiovascular (CV) function. Ten men completed four trials in which they exercised in a 35 degrees C environment until dehydrated by 2. 9% body mass, were rehydrated for 180 min, and exercised for an additional 20 min. Four RH regimens were tested: low volume (100% fluid replacement)-low (25 mM) Na(+) (LL), low volume-high (50 mM) Na(+) (LH), high volume (150% fluid replacement)-low Na(+) (HL), and high volume-high Na(+) (HH). Blood and urine samples were collected and body mass was measured before and after exercise and every hour during RH. Before and after the dehydration exercise and during the 20 min of exercise after RH, cardiac output was measured. Fluid compartment (intracellular and extracellular) restoration and percent change in plasma volume were calculated using the Cl(-) and hematocrit/Hb methods, respectively. RH was greater (P < 0.05) in HL and HH (102.0 +/- 15.2 and 103.7 +/- 14.7%, respectively) than in LL and LH (70.7 +/- 10.5 and 75.9 +/- 6.3%, respectively). Intracellular RH was greater in HL (1.12 +/- 0.4 liters) than in all other conditions (0.83 +/- 0.3, 0.69 +/- 0.2, and 0.73 +/- 0.3 liter for LL, LH, and HH, respectively), whereas extracellular RH (including plasma volume) was greater in HL and HH (1.35 +/- 0.8 and 1.63 +/- 0.4 liters, respectively) than in LL and LH (0.83 +/- 0.3 and 1.05 +/- 0.4 liters, respectively). CV function (based on stroke volume, heart rate, and cardiac output) was restored equally in all conditions. These data indicate that greater RH can be achieved through larger volumes of fluid and is not affected by Na(+) content within the range tested. Higher Na(+) content favors extracellular fluid filling, whereas intracellular fluid benefits from higher volumes of fluid with lower Na(+). Alterations in Na(+) and/or volume within the range tested do not affect the degree of restoration of CV function.
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Quantitative comparison of functional contrast from BOLD-weighted spin-echo and gradient-echo echoplanar imaging at 1.5 Tesla and H2 15O PET in the whole brain. J Cereb Blood Flow Metab 2000; 20:1331-40. [PMID: 10994855 DOI: 10.1097/00004647-200009000-00008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Spin-echo and gradient-echo echoplanar functional magnetic resonance imaging (fMRI) studies at 1.5 Tesla (T) were used to obtain blood oxygenation level-dependent (BOLD) contrast images of the whole brain in seven strongly right-handed women during execution of a complex motor task. Five subjects underwent subsequent H215O positron emission tomography (PET) studies while performing the same task. Group-averaged results for changes in the MRI relaxation rates R2* and R2 at 1.5T in response to neuronal activation in nine cortical, subcortical, and cerebellar motor regions are reported. Results for each method are grouped according to tissue type-cerebral cortex (precentral gyrus and supplementary motor area), subcortical regions (thalamus and putamen), and cerebellar cortex (superior lobule). The observed changes in R2* from activation-induced oxygenation changes were more variable across brain regions with different tissue characteristics than observed changes in R2. The ratio of deltaR2* to deltaR2 was 3.3 +/- 0.9 for cerebral cortex and 2.0 +/- 0.6 for subcortical tissue. deltaR2*, deltaR2, and relative blood flow changes were deltaR2* = -0.201 +/- 0.040 (s-1), deltaR2 = -0.064 +/- 0.011 s(-1), and deltaf/f = 16.7 +/- 0.8% in the cerebral cortex; deltaR2* = -0.100 +/- 0.026 s(-1), deltaR2 = -0.049 +/- 0.009 s(-1), and deltaf/f = 9.4 +/- 0.7% in the subcortical regions; and deltaR2* = -0.215 +/- 0.093 s(-1), deltaR2 = -0.069 +/- 0.012 s(-1), and deltaf/f = 16.2 +/- 1.2% in the cerebellar cortex.
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Serial analysis of magnetization-transfer histograms and Expanded Disability Status Scale scores in patients with relapsing-remitting multiple sclerosis. AJNR Am J Neuroradiol 1999; 20:1946-50. [PMID: 10588123 PMCID: PMC7657806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
BACKGROUND AND PURPOSE Magnetization transfer ratio histogram peak height (MTR-HPH) has been shown to correlate with macroscopic and microscopic brain disease in patients with multiple sclerosis (MS). We studied the changes in MTR-HPH and in Kurtzke's Expanded Disability Status Scale (EDSS) scores over time in a group of patients with relapsing-remitting MS. METHODS Twenty adult patients with relapsing-remitting MS (four men and 16 women) were followed up for a period of 334 to 1313 days. In all, 86 MR imaging studies of the brain were obtained, and MTR-HPH was calculated for each MR examination by using a semiautomated technique. Changes in MTR-HPH were compared between patients over the study's duration. A neurologist specialized in the care of MS patients assessed the EDSS score for each patient as a measure of clinical disability. RESULTS Serial MR data showed a subtle but significant decline in MTR-HPH with time. No significant changes in EDSS scores were noted over the same period. CONCLUSION Patients with relapsing-remitting MS have a significant progressive decline in normalized MTR-HPH, which is independent of EDSS score. MTR-HPH measurements can be used to monitor subclinical disease in patients with relapsing-remitting MS over a short time frame of 1 to 4 years. This parameter might be applied in future therapeutic trials to assess its usefulness.
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Differences between relapsing-remitting and chronic progressive multiple sclerosis as determined with quantitative MR imaging. Radiology 1999; 210:769-74. [PMID: 10207480 DOI: 10.1148/radiology.210.3.r99mr44769] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To investigate the cross-sectional relationships among multiple quantitative brain magnetic resonance (MR) imaging measurements in patients with relapsing-remitting versus chronic progressive multiple sclerosis (MS). MATERIALS AND METHODS Thirty-eight patients with MS (relapsing-remitting, 26, chronic progressive, 12) were examined. Lesion volume on T2-weighted MR images, contrast material-enhancing lesion volume, percentage of brain parenchymal volume (brain volume/[brain volume + cerebrospinal fluid volume), and magnetization transfer ratio histogram peak height for the whole brain were calculated. RESULTS Significant negative correlation was noted between volume on T2-weighted images and magnetization transfer ratio histogram peak height for both the relapsing-remitting and chronic progressive groups (P < .001 for both). A positive correlation was demonstrated for lesion volume on T2-weighted images and enhancing lesion volume in the relapsing-remitting group (P < .01) but not in the chronic progressive group. Negative correlations were demonstrated for enhancing lesion volume and magnetization transfer ratio histogram peak height (P = .02), for Expanded Disability Status Scale score and magnetization transfer histogram peak height (P = .02), and for Expanded Disability Status Scale score and percentage of brain parenchymal volume in the relapsing-remitting group (P = .004) but not in the chronic progressive group. CONCLUSION The cross-sectional relationships among multiple quantitative brain MR imaging measurements are different between relapsing-remitting and chronic progressive MS.
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Diffusion imaging in pediatric hypoxic ischemia injury. Neuroimaging Clin N Am 1999; 9:41-52. [PMID: 9974498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
This article is a brief review on the physics of diffusion imaging as well as the pertinent adult literature regarding stroke and diffusion imaging. The remainder of the article focuses on the potential uses of diffusion imaging for the evaluation of hypoxic ischemia injury in pediatric populations. In particular, diffusion changes in hypoxic ischemia injury in newborns are reviewed as the diffusion abnormalities in immature brain may behave in a manner different from adults.
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Abstract
RATIONALE AND OBJECTIVES Abdominal radiologists actively participated and provided subspecialty radiologic expertise in a multidisciplinary gastrointestinal cancer clinic that served a tertiary referral center. The purpose of this study was to evaluate the feasibility and nonradiologists' opinions of this new approach to radiologic consultation. MATERIALS AND METHODS One of four subspecialty-trained abdominal radiologists joined physicians from four other subspecialties in staffing weekly 4-hour clinic sessions. Images were reviewed, opinions on test selection and interventional options rendered, and patients met with when interventional options were considered. Radiologists were compensated a fixed sum for each session. A survey of nonradiologists' opinions about the radiologists' active participation was conducted after 15 months (61 clinic sessions). RESULTS Abdominal radiologists' active participation was feasible and highly regarded by nonradiologist physicians. Specific benefits cited in the survey included improved interpretation, more efficient use of nonradiologist physician time, and improved rapport between radiologists and nonradiologists. Nonradiologist physicians believed that patient care was improved and that the radiologists' participation should continue. CONCLUSION The active participation of abdominal radiologists in a multidisciplinary gastrointestinal cancer clinic is feasible and highly regarded by nonradiologists.
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Negative predictive value of imaging-guided abdominal biopsy results: cytologic classification and implications for patient management. AJR Am J Roentgenol 1998; 171:693-6. [PMID: 9725298 DOI: 10.2214/ajr.171.3.9725298] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Our purpose was to assess the negative predictive value of imaging-guided abdominal biopsy results and correlate it with cytology classification, lesion size, needle gauge, and cancer history. MATERIALS AND METHODS A retrospective study was performed of 100 patients with proven diagnoses who had undergone imaging-guided abdominal biopsies showing no cells that were malignant or suspicious for malignancy. Specimens were classified as normal or benign, nondiagnostic, or atypical. Negative predictive value was calculated for each cytologic category, lesion size, needle gauge, and cancer history. Logistic regression analysis was performed to allow us to identify predictors of false-negative results. RESULTS Overall negative predictive value was 67%. Other negative predictive values were normal or benign result, 78%; nondiagnostic result, 66%; and atypical result, 29%. Negative predictive value was greater when the lesion was large (> or =3 cm) (p = .031). Logistic regression analysis allowed us to predict a 9.3% chance of a false-negative result for a specimen of normal or benign cytology that was taken from a large lesion in a patient with no cancer history but an 87% chance of a false-negative when a specimen of atypical cytology was taken from a small (<3 cm) lesion in a patient with a cancer history. CONCLUSION Imaging-guided abdominal biopsy specimens containing atypical cells should be viewed with caution. In patients without cancer, if a lesion is large and the specimen contains normal target organ or benign cells, the likelihood of a false-negative result may be low enough that imaging surveillance at appropriate intervals may be sufficient.
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Abstract
This review focuses on new developments in the pathophysiology and treatment of von Willebrand disease (vWd). New aspects of the cell biology, gene control, and structure-function correlates of von Willebrand factor (vWf) are reviewed. vWd is more prevalent than previously recognized, affecting up to 1% of the population; this is particularly evident in women's health. Blood group is an important determinant of von Willebrand factor levels; individuals of blood group O tend to have lower plasma levels of vWf than those in other blood groups. Currently available blood tests of vWf quantity and function are discussed, in addition to newer tests undergoing validation. Treatment of classical vWd with desmopressin acetate and plasma derivatives is discussed, as is the potential for intravenous immunoglobulin and corticosteroids in acquired vWd. Special situations, such as the management of vWd in pregnancy, are also discussed.
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Abstract
PURPOSE To determine the difference in cost to providers of percutaneous abdominal biopsy as the first strategy versus surgical biopsy. MATERIALS AND METHODS Cost of tissue diagnosis determination with percutaneous biopsy as the first strategy in 439 patients with an abdominal mass was estimated. Costs included direct hospital costs and professional costs of initial and repeat biopsy, follow-up imaging and clinic visits, surgical biopsy (when needed), and treatment of complications. The sum of these costs was compared with the estimated cost had the same patients undergone surgical biopsy instead, with no complications or need for follow-up or repeat biopsy. RESULTS The total estimated cost of percutaneous biopsy as the first strategy ($543,245) was less than the cost had surgical biopsy been used alone ($1,919,867). The average per patient direct hospital cost of percutaneous biopsy ($800) was lower than that of surgical biopsy ($3,419). The average per patient professional cost of percutaneous biopsy ($438) was also lower than that of surgical biopsy ($955). Savings averaged $3,136 per patient, or $1,376,622 for the study period. CONCLUSION Substantial health care cost savings may result by using a diagnostic algorithm in which percutaneous biopsy is the first strategy for establishment of a diagnosis in patients suspected of having abdominal malignancy.
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Comparison of T2 lesion volume and magnetization transfer ratio histogram analysis and of atrophy and measures of lesion burden in patients with multiple sclerosis. AJNR Am J Neuroradiol 1998; 19:1055-60. [PMID: 9672011 PMCID: PMC8338648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE The purpose of this study was twofold: first, to compare two different measures of lesion burden in patients with multiple sclerosis (MS), the magnetization transfer ratio (MTR) histogram and T2 lesion volume; and, second, to investigate the relationship between lesion burden and atrophy in patients with MS. METHODS Thirty patients with MS were examined with MR imaging, including fast spin-echo T2- and proton density-weighted sequences as well as magnetization transfer sequences. The lesion burden in each subject was quantitated by MTR histographic analysis and by a computer-based method for calculating the total volume of lesions on T2-weighted images. Additionally, the CSF volume, the brain parenchymal volume, and the percentage of brain parenchymal volume were determined in all patients by using this method and were compared with measurements in eight control subjects. RESULTS Significant loss of parenchymal volume was seen in patients with MS as determined by increased CSF volume and decreased percentage of brain parenchymal volume relative to that in age-matched control subjects. An inverse correlation was observed between the peak height of the MTR histogram and T2 lesion volume. T2 lesion volume corresponded positively with CSF volume and inversely with percentage of brain parenchymal volume. The peak height of the MTR histogram corresponded positively with percentage of brain parenchymal volume and inversely with CSF volume. CONCLUSION MS patients sustain a significant loss of parenchymal volume (atrophy), which corresponds strongly with increasing lesion burden. T2 lesion volume and peak height of the MTR histogram show good correlation, and the peak height of the MTR histogram shows a superior correlation with measures of brain atrophy as compared with measurements of T2 lesion volume, suggesting that the MTR histogram may be a better indicator of global disease burden than is T2 lesion volume.
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Abstract
BACKGROUND Acquired autoantibodies to factor VIII in patients without hemophilia are rare, but they cause severe illness and death if not eradicated. OBJECTIVE To examine daily therapy with oral cyclophosphamide and prednisone for acquired hemophilia. DESIGN Case series. SETTING Academic medical center. PATIENTS Nine consecutive patients without hemophilia who had severe hemorrhage caused by high titers of factor VIII inhibitors. INTERVENTIONS Daily oral cyclophosphamide and prednisone. Coagulation factors were used only for bleeding. MEASUREMENTS Plasma titers of factor VIII inhibitor, factor VIII activity, and clinical evidence of bleeding. RESULTS All patients achieved complete remission, which was defined as loss of residual inhibitor activity and return to a normal titer of factor VIII. Therapy lasted a median of 12 weeks (range, 3 to 37 weeks). Bleeding resolved in a median of 3 weeks (range, 2 to 10 weeks). Median follow-up after discontinuation of therapy was 91 weeks (range, 61 to 164 weeks). CONCLUSION Daily administration of oral cyclophosphamide and prednisone without empirical factor VIII therapy seems to be an effective and well-tolerated treatment for acquired hemophilia.
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These are challenging times for not-for profit boards. TRUSTEE : THE JOURNAL FOR HOSPITAL GOVERNING BOARDS 1997; 50:30, 32. [PMID: 10168861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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