1
|
Morris JN, Fries BE, Mehr DR, Hawes C, Phillips C, Mor V, Lipsitz LA. MDS Cognitive Performance Scale. JOURNAL OF GERONTOLOGY 1994; 49:M174-82. [PMID: 8014392 DOI: 10.1093/geronj/49.4.m174] [Citation(s) in RCA: 1362] [Impact Index Per Article: 43.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Chronic cognitive impairment is a major problem in U.S. nursing homes, yet traditional assessment systems in most facilities included only limited information on cognitive status. Following the Congressional mandate in the Omnibus Reconciliation Act of 1987 (OBRA '87), U.S. nursing homes now complete the Minimum Data Set (MDS), a standardized, comprehensive assessment of each resident's functional, medical, psychosocial, and cognitive status. We designed a Cognitive Performance Scale (CPS) that uses MDS data to assign residents into easily understood cognitive performance categories. METHODS Information was drawn from three data sets, including two multistate data sets constructed for the Health Care Financing Administration. The prevalence and reliability of the MDS cognitive performance variables were established when assessed by trained nursing personnel. Five selected MDS items were combined to create the single, functionally meaningful seven-category hierarchical Cognitive Performance Scale. RESULTS The CPS scale corresponded closely with scores generated by the Mini-Mental State Examination and the Test for Severe Impairment, nursing judgments of disorientation, and neurological diagnoses of Alzheimer's disease and other dementias. CONCLUSIONS The new CPS provides a functional view of cognitive performance, using readily available MDS data. It should prove useful to clinicians and investigators using the MDS to determine a resident's cognitive assets.
Collapse
|
Multicenter Study |
31 |
1362 |
2
|
Plassman BL, Havlik RJ, Steffens DC, Helms MJ, Newman TN, Drosdick D, Phillips C, Gau BA, Welsh-Bohmer KA, Burke JR, Guralnik JM, Breitner JC. Documented head injury in early adulthood and risk of Alzheimer's disease and other dementias. Neurology 2000; 55:1158-66. [PMID: 11071494 DOI: 10.1212/wnl.55.8.1158] [Citation(s) in RCA: 598] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The association between antecedent head injury and AD is inconsistent. OBJECTIVE To examine the association between early adult head injury, as documented by military hospital records, and dementia in late life; and to evaluate the interaction between head injury and APOE epsilon4 as risk factors for dementia. METHODS The study had a population-based prospective historical cohort design. It included men who were World War II Navy and Marine veterans, and were hospitalized during their military service with a diagnosis of either a nonpenetrating head injury or another unrelated condition. In 1996 to 1997, military medical records were abstracted to document the occurrence and details of closed head injury. The entire sample was then evaluated for dementia and AD using a multistage procedure. There were 548 veterans with head injury and 1228 without head injury who completed all assigned stages of the study. The authors estimated risk of dementia, specifically AD, using proportional hazards models. RESULTS Both moderate head injury (hazard ratio [HR] = 2.32; CI = 1.04 to 5.17) and severe head injury (HR = 4.51; CI = 1.77 to 11.47) were associated with increased risk of AD. Results were similar for dementia in general. The results for mild head injury were inconclusive. When the authors stratified by the number of APOE epsilon4 alleles, they observed a nonsignificant trend toward a stronger association between AD and head injury in men with more epsilon4 alleles. CONCLUSIONS Moderate and severe head injuries in young men may be associated with increased risk of AD and other dementias in late life. However, the authors cannot exclude the possibility that other unmeasured factors may be influencing this association.
Collapse
|
|
25 |
598 |
3
|
Friston KJ, Glaser DE, Henson RNA, Kiebel S, Phillips C, Ashburner J. Classical and Bayesian inference in neuroimaging: applications. Neuroimage 2002; 16:484-512. [PMID: 12030833 DOI: 10.1006/nimg.2002.1091] [Citation(s) in RCA: 558] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In Friston et al. ((2002) Neuroimage 16: 465-483) we introduced empirical Bayes as a potentially useful way to estimate and make inferences about effects in hierarchical models. In this paper we present a series of models that exemplify the diversity of problems that can be addressed within this framework. In hierarchical linear observation models, both classical and empirical Bayesian approaches can be framed in terms of covariance component estimation (e.g., variance partitioning). To illustrate the use of the expectation-maximization (EM) algorithm in covariance component estimation we focus first on two important problems in fMRI: nonsphericity induced by (i) serial or temporal correlations among errors and (ii) variance components caused by the hierarchical nature of multisubject studies. In hierarchical observation models, variance components at higher levels can be used as constraints on the parameter estimates of lower levels. This enables the use of parametric empirical Bayesian (PEB) estimators, as distinct from classical maximum likelihood (ML) estimates. We develop this distinction to address: (i) The difference between response estimates based on ML and the conditional means from a Bayesian approach and the implications for estimates of intersubject variability. (ii) The relationship between fixed- and random-effect analyses. (iii) The specificity and sensitivity of Bayesian inference and, finally, (iv) the relative importance of the number of scans and subjects. The forgoing is concerned with within- and between-subject variability in multisubject hierarchical fMRI studies. In the second half of this paper we turn to Bayesian inference at the first (within-voxel) level, using PET data to show how priors can be derived from the (between-voxel) distribution of activations over the brain. This application uses exactly the same ideas and formalism but, in this instance, the second level is provided by observations over voxels as opposed to subjects. The ensuing posterior probability maps (PPMs) have enhanced anatomical precision and greater face validity, in relation to underlying anatomy. Furthermore, in comparison to conventional SPMs they are not confounded by the multiple comparison problem that, in a classical context, dictates high thresholds and low sensitivity. We conclude with some general comments on Bayesian approaches to image analysis and on some unresolved issues.
Collapse
|
|
23 |
558 |
4
|
Burrows AB, Morris JN, Simon SE, Hirdes JP, Phillips C. Development of a minimum data set-based depression rating scale for use in nursing homes. Age Ageing 2000; 29:165-72. [PMID: 10791452 DOI: 10.1093/ageing/29.2.165] [Citation(s) in RCA: 516] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND depression is common but under-diagnosed in nursing-home residents. There is a need for a standardized screening instrument which incorporates daily observations of nursing-home staff. AIM to develop and validate a screening instrument for depression using items from the Minimum Data Set of the Resident Assessment Instrument. METHODS we conducted semi-structured interviews with 108 residents from two nursing homes to obtain depression ratings using the 17-item Hamilton Depression Rating Scale and the Cornell Scale for Depression in Dementia. Nursing staff completed Minimum Data Set assessments. In a randomly assigned derivation sample (n = 81), we identified Minimum Data Set mood items that were correlated (P < 0.05) with Hamilton and Cornell ratings. These items were factored using an oblique rotation to yield five conceptually distinct factors. Using linear regression, each set of factored items was regressed against Hamilton and Cornell ratings to identify a core set of seven Minimum Data Set mood items which comprise the Minimum Data Set Depression Rating Scale. We then tested the performance of the Minimum Data Set Depression Rating Scale against accepted cut-offs and psychiatric diagnoses. RESULTS a cutpoint score of 3 on the Minimum Data Set Depression Rating Scale maximized sensitivity (94% for Hamilton, 78% for Cornell) with minimal loss of specificity (72% for Hamilton, 77% for Cornell) when tested against cut-offs for mild to moderate depression in the derivation sample. Results were similar in the validation sample. When tested against diagnoses of major or non-major depression in a subset of 82 subjects, sensitivity was 91% and specificity was 69%. Performance compared favourably with the 15-item Geriatric Depression Scale. CONCLUSION items from the Minimum Data Set can be organized to screen for depression in nursing-home residents. Further testing of the instrument is now needed.
Collapse
|
|
25 |
516 |
5
|
Fortin PR, Clarke AE, Joseph L, Liang MH, Tanzer M, Ferland D, Phillips C, Partridge AJ, Bélisle P, Fossel AH, Mahomed N, Sledge CB, Katz JN. Outcomes of total hip and knee replacement: preoperative functional status predicts outcomes at six months after surgery. ARTHRITIS AND RHEUMATISM 1999; 42:1722-8. [PMID: 10446873 DOI: 10.1002/1529-0131(199908)42:8<1722::aid-anr22>3.0.co;2-r] [Citation(s) in RCA: 516] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To determine whether patients with knee or hip osteoarthritis (OA) who have worse physical function preoperatively achieve a postoperative status that is similar to that of patients with better preoperative function. METHODS This study surveyed an observational cohort of 379 consecutive patients with definite OA who were without other inflammatory joint diseases and were undergoing either total hip or knee replacement in a US (Boston) and a Canadian (Montreal) referral center. Questionnaires on health status (the Short Form 36 and Western Ontario and McMaster Universities Osteoarthritis Index) were administered preoperatively and at 3 and 6 months postoperatively. Physical function and pain due to OA were deemed the most significant outcomes to study. RESULTS Two hundred twenty-two patients returned their questionnaires. Patients in the 2 centers were comparable in age, sex, time to surgery, and proportion of hip/knee surgery. The Boston group had more education, lower comorbidity, and more cemented knee prostheses. Patients undergoing hip or knee replacement in Montreal had lower preoperative physical function and more pain than their Boston counterparts. In patients with lower preoperative physical function, function and pain were not improved postoperatively to the level achieved by those with higher preoperative function. This was most striking in patients undergoing total knee replacement. CONCLUSION Surgery performed later in the natural history of functional decline due to OA of the knee, and possibly of the hip, results in worse postoperative functional status.
Collapse
|
|
26 |
516 |
6
|
Maquet P, Laureys S, Peigneux P, Fuchs S, Petiau C, Phillips C, Aerts J, Del Fiore G, Degueldre C, Meulemans T, Luxen A, Franck G, Van Der Linden M, Smith C, Cleeremans A. Experience-dependent changes in cerebral activation during human REM sleep. Nat Neurosci 2000; 3:831-6. [PMID: 10903578 DOI: 10.1038/77744] [Citation(s) in RCA: 413] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The function of rapid-eye-movement (REM) sleep is still unknown. One prevailing hypothesis suggests that REM sleep is important in processing memory traces. Here, using positron emission tomography (PET) and regional cerebral blood flow measurements, we show that waking experience influences regional brain activity during subsequent sleep. Several brain areas activated during the execution of a serial reaction time task during wakefulness were significantly more active during REM sleep in subjects previously trained on the task than in non-trained subjects. These results support the hypothesis that memory traces are processed during REM sleep in humans.
Collapse
|
|
25 |
413 |
7
|
Boly M, Balteau E, Schnakers C, Degueldre C, Moonen G, Luxen A, Phillips C, Peigneux P, Maquet P, Laureys S. Baseline brain activity fluctuations predict somatosensory perception in humans. Proc Natl Acad Sci U S A 2007; 104:12187-92. [PMID: 17616583 PMCID: PMC1924544 DOI: 10.1073/pnas.0611404104] [Citation(s) in RCA: 402] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Indexed: 11/18/2022] Open
Abstract
In perceptual experiments, within-individual fluctuations in perception are observed across multiple presentations of the same stimuli, a phenomenon that remains only partially understood. Here, by means of thulium-yttrium/aluminum-garnet laser and event-related functional MRI, we tested whether variability in perception of identical stimuli relates to differences in prestimulus, baseline brain activity. Results indicate a positive relationship between conscious perception of low-intensity somatosensory stimuli and immediately preceding levels of baseline activity in medial thalamus and the lateral frontoparietal network, respectively, which are thought to relate to vigilance and "external monitoring." Conversely, there was a negative correlation between subsequent reporting of conscious perception and baseline activity in a set of regions encompassing posterior cingulate/precuneus and temporoparietal cortices, possibly relating to introspection and self-oriented processes. At nociceptive levels of stimulation, pain-intensity ratings positively correlated with baseline fluctuations in anterior cingulate cortex in an area known to be involved in the affective dimension of pain. These results suggest that baseline brain-activity fluctuations may profoundly modify our conscious perception of the external world.
Collapse
|
Clinical Trial |
18 |
402 |
8
|
Palmer EA, Flynn JT, Hardy RJ, Phelps DL, Phillips CL, Schaffer DB, Tung B. Incidence and early course of retinopathy of prematurity. The Cryotherapy for Retinopathy of Prematurity Cooperative Group. Ophthalmology 1991; 98:1628-40. [PMID: 1800923 DOI: 10.1016/s0161-6420(91)32074-8] [Citation(s) in RCA: 396] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (ROP), 4099 infants weighing less than 1251 g at birth underwent sequential ophthalmic examinations, beginning at age 4 to 6 weeks, to monitor the incidence and course of ROP. Overall, 65.8% of the infants developed ROP to some degree; 81.6% for infants of less than 1000 g birth weight. As expected, ROP incidence and severity were higher in lower birth weight and gestational age categories. Black infants appeared less susceptible to ROP, of all severity categories, than nonblack infants. The timing of retinal vascular events correlated more closely with postconceptional age than with postnatal age, implicating the level of maturity more than postnatal environmental influences in governing the timing of these vascular events. These results include the current incidence of various severity stages of ROP found in the United States and provide new insight into the development of ROP.
Collapse
|
Clinical Trial |
34 |
396 |
9
|
Friston KJ, Penny W, Phillips C, Kiebel S, Hinton G, Ashburner J. Classical and Bayesian inference in neuroimaging: theory. Neuroimage 2002; 16:465-83. [PMID: 12030832 DOI: 10.1006/nimg.2002.1090] [Citation(s) in RCA: 387] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This paper reviews hierarchical observation models, used in functional neuroimaging, in a Bayesian light. It emphasizes the common ground shared by classical and Bayesian methods to show that conventional analyses of neuroimaging data can be usefully extended within an empirical Bayesian framework. In particular we formulate the procedures used in conventional data analysis in terms of hierarchical linear models and establish a connection between classical inference and parametric empirical Bayes (PEB) through covariance component estimation. This estimation is based on an expectation maximization or EM algorithm. The key point is that hierarchical models not only provide for appropriate inference at the highest level but that one can revisit lower levels suitably equipped to make Bayesian inferences. Bayesian inferences eschew many of the difficulties encountered with classical inference and characterize brain responses in a way that is more directly predicated on what one is interested in. The motivation for Bayesian approaches is reviewed and the theoretical background is presented in a way that relates to conventional methods, in particular restricted maximum likelihood (ReML). This paper is a technical and theoretical prelude to subsequent papers that deal with applications of the theory to a range of important issues in neuroimaging. These issues include; (i) Estimating nonsphericity or variance components in fMRI time-series that can arise from serial correlations within subject, or are induced by multisubject (i.e., hierarchical) studies. (ii) Spatiotemporal Bayesian models for imaging data, in which voxels-specific effects are constrained by responses in other voxels. (iii) Bayesian estimation of nonlinear models of hemodynamic responses and (iv) principled ways of mixing structural and functional priors in EEG source reconstruction. Although diverse, all these estimation problems are accommodated by the PEB framework described in this paper.
Collapse
|
Comparative Study |
23 |
387 |
10
|
Ponting CP, Phillips C, Davies KE, Blake DJ. PDZ domains: targeting signalling molecules to sub-membranous sites. Bioessays 1997; 19:469-79. [PMID: 9204764 DOI: 10.1002/bies.950190606] [Citation(s) in RCA: 338] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PDZ (also called DHR or GLGF) domains are found in diverse membrane-associated proteins including members of the MAGUK family of guanylate kinase homologues, several protein phosphatases and kinases, neuronal nitric oxide synthase, and several dystrophin-associated proteins, collectively known as syntrophins. Many PDZ domain-containing proteins appear to be localised to highly specialised submembranous sites, suggesting their participation in cellular junction formation, receptor or channel clustering, and intracellular signalling events. PDZ domains of several MAGUKs interact with the C-terminal polypeptides of a subset of NMDA receptor subunits and/or with Shaker-type K+ channels. Other PDZ domains have been shown to bind similar ligands of other transmembrane receptors. Recently, the crystal structures of PDZ domains, with and without ligand, have been determined. These demonstrate the mode of ligand-binding and the structural bases for sequence conservation among diverse PDZ domains.
Collapse
|
Review |
28 |
338 |
11
|
Laureys S, Goldman S, Phillips C, Van Bogaert P, Aerts J, Luxen A, Franck G, Maquet P. Impaired effective cortical connectivity in vegetative state: preliminary investigation using PET. Neuroimage 1999; 9:377-82. [PMID: 10191166 DOI: 10.1006/nimg.1998.0414] [Citation(s) in RCA: 254] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Vegetative state (VS) is a condition of abolished awareness with persistence of arousal. Awareness is part of consciousness, which itself is thought to represent an emergent property of cerebral neural networks. Our hypothesis was that part of the neural correlate underlying VS is an altered connectivity, especially between the associative cortices. We assessed regional cerebral glucose metabolism (rCMRGlu) and effective cortical connectivity in four patients in VS by means of statistical parametric mapping and [18F]fluorodeoxyglucose-positron emission tomography. Our data showed a common pattern of impaired rCMRGlu in the prefrontal, premotor, and parietotemporal association areas and posterior cingulate cortex/precuneus in VS. In a next step, we demonstrated that in VS patients various prefrontal and premotor areas have in common that they are less tightly connected with the posterior cingulate cortex than in normal controls. These results provide a strong argument for an alteration of cortical connectivity in VS patients.
Collapse
|
Case Reports |
26 |
254 |
12
|
Boly M, Phillips C, Tshibanda L, Vanhaudenhuyse A, Schabus M, Dang-Vu TT, Moonen G, Hustinx R, Maquet P, Laureys S. Intrinsic brain activity in altered states of consciousness: how conscious is the default mode of brain function? Ann N Y Acad Sci 2008; 1129:119-29. [PMID: 18591474 PMCID: PMC2855379 DOI: 10.1196/annals.1417.015] [Citation(s) in RCA: 243] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Spontaneous brain activity has recently received increasing interest in the neuroimaging community. However, the value of resting-state studies to a better understanding of brain-behavior relationships has been challenged. That altered states of consciousness are a privileged way to study the relationships between spontaneous brain activity and behavior is proposed, and common resting-state brain activity features observed in various states of altered consciousness are reviewed. Early positron emission tomography studies showed that states of extremely low or high brain activity are often associated with unconsciousness. However, this relationship is not absolute, and the precise link between global brain metabolism and awareness remains yet difficult to assert. In contrast, voxel-based analyses identified a systematic impairment of associative frontoparieto-cingulate areas in altered states of consciousness, such as sleep, anesthesia, coma, vegetative state, epileptic loss of consciousness, and somnambulism. In parallel, recent functional magnetic resonance imaging studies have identified structured patterns of slow neuronal oscillations in the resting human brain. Similar coherent blood oxygen level-dependent (BOLD) systemwide patterns can also be found, in particular in the default-mode network, in several states of unconsciousness, such as coma, anesthesia, and slow-wave sleep. The latter results suggest that slow coherent spontaneous BOLD fluctuations cannot be exclusively a reflection of conscious mental activity, but may reflect default brain connectivity shaping brain areas of most likely interactions in a way that transcends levels of consciousness, and whose functional significance remains largely in the dark.
Collapse
|
Review |
17 |
243 |
13
|
Cevidanes LHS, Bailey LJ, Tucker GR, Styner MA, Mol A, Phillips CL, Proffit WR, Turvey T. Superimposition of 3D cone-beam CT models of orthognathic surgery patients. Dentomaxillofac Radiol 2006; 34:369-75. [PMID: 16227481 PMCID: PMC3552302 DOI: 10.1259/dmfr/17102411] [Citation(s) in RCA: 231] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To evaluate the registration of 3D models from cone-beam CT (CBCT) images taken before and after orthognathic surgery for the assessment of mandibular anatomy and position. METHODS CBCT scans were taken before and after orthognathic surgery for ten patients with various malocclusions undergoing maxillary surgery only. 3D models were constructed from the CBCT images utilizing semi-automatic segmentation and manual editing. The cranial base was used to register 3D models of pre- and post-surgery scans (1 week). After registration, a novel tool allowed the visual and quantitative assessment of post-operative changes via 2D overlays of superimposed models and 3D coloured displacement maps. RESULTS 3D changes in mandibular rami position after surgical procedures were clearly illustrated by the 3D colour-coded maps. The average displacement of all surfaces was 0.77 mm (SD=0.17 mm), at the posterior border 0.78 mm (SD=0.25 mm), and at the condyle 0.70 mm (SD=0.07 mm). These displacements were close to the image spatial resolution of 0.60 mm. The average interobserver differences were negligible. The range of the interobserver errors for the average of all mandibular rami surface distances was 0.02 mm (SD=0.01 mm). CONCLUSION Our results suggest this method provides a valid and reproducible assessment of craniofacial structures for patients undergoing orthognathic surgery. This technique may be used to identify different patterns of ramus and condylar remodelling following orthognathic surgery.
Collapse
|
Journal Article |
19 |
231 |
14
|
Boly M, Tshibanda L, Vanhaudenhuyse A, Noirhomme Q, Schnakers C, Ledoux D, Boveroux P, Garweg C, Lambermont B, Phillips C, Luxen A, Moonen G, Bassetti C, Maquet P, Laureys S. Functional connectivity in the default network during resting state is preserved in a vegetative but not in a brain dead patient. Hum Brain Mapp 2009; 30:2393-400. [PMID: 19350563 DOI: 10.1002/hbm.20672] [Citation(s) in RCA: 228] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Recent studies on spontaneous fluctuations in the functional MRI blood oxygen level-dependent (BOLD) signal in awake healthy subjects showed the presence of coherent fluctuations among functionally defined neuroanatomical networks. However, the functional significance of these spontaneous BOLD fluctuations remains poorly understood. By means of 3 T functional MRI, we demonstrate absent cortico-thalamic BOLD functional connectivity (i.e. between posterior cingulate/precuneal cortex and medial thalamus), but preserved cortico-cortical connectivity within the default network in a case of vegetative state (VS) studied 2.5 years following cardio-respiratory arrest, as documented by extensive behavioral and paraclinical assessments. In the VS patient, as in age-matched controls, anticorrelations could also be observed between posterior cingulate/precuneus and a previously identified task-positive cortical network. Both correlations and anticorrelations were significantly reduced in VS as compared to controls. A similar approach in a brain dead patient did not show any such long-distance functional connectivity. We conclude that some slow coherent BOLD fluctuations previously identified in healthy awake human brain can be found in alive but unaware patients, and are thus unlikely to be uniquely due to ongoing modifications of conscious thoughts. Future studies are needed to give a full characterization of default network connectivity in the VS patients population.
Collapse
|
Research Support, Non-U.S. Gov't |
16 |
228 |
15
|
Bannister KW, Deller AT, Phillips C, Macquart JP, Prochaska JX, Tejos N, Ryder SD, Sadler EM, Shannon RM, Simha S, Day CK, McQuinn M, North-Hickey FO, Bhandari S, Arcus WR, Bennert VN, Burchett J, Bouwhuis M, Dodson R, Ekers RD, Farah W, Flynn C, James CW, Kerr M, Lenc E, Mahony EK, O'Meara J, Osłowski S, Qiu H, Treu T, U V, Bateman TJ, Bock DCJ, Bolton RJ, Brown A, Bunton JD, Chippendale AP, Cooray FR, Cornwell T, Gupta N, Hayman DB, Kesteven M, Koribalski BS, MacLeod A, McClure-Griffiths NM, Neuhold S, Norris RP, Pilawa MA, Qiao RY, Reynolds J, Roxby DN, Shimwell TW, Voronkov MA, Wilson CD. A single fast radio burst localized to a massive galaxy at cosmological distance. Science 2019; 365:565-570. [PMID: 31249136 DOI: 10.1126/science.aaw5903] [Citation(s) in RCA: 220] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 06/19/2019] [Indexed: 11/03/2022]
Abstract
Fast radio bursts (FRBs) are brief radio emissions from distant astronomical sources. Some are known to repeat, but most are single bursts. Nonrepeating FRB observations have had insufficient positional accuracy to localize them to an individual host galaxy. We report the interferometric localization of the single-pulse FRB 180924 to a position 4 kiloparsecs from the center of a luminous galaxy at redshift 0.3214. The burst has not been observed to repeat. The properties of the burst and its host are markedly different from those of the only other accurately localized FRB source. The integrated electron column density along the line of sight closely matches models of the intergalactic medium, indicating that some FRBs are clean probes of the baryonic component of the cosmic web.
Collapse
|
Research Support, Non-U.S. Gov't |
6 |
220 |
16
|
Maupin P, Phillips CL, Adelstein RS, Pollard TD. Differential localization of myosin-II isozymes in human cultured cells and blood cells. J Cell Sci 1994; 107 ( Pt 11):3077-90. [PMID: 7699007 DOI: 10.1242/jcs.107.11.3077] [Citation(s) in RCA: 193] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We used purified polyclonal antibodies to human cytoplasmic myosin-IIA and myosin-IIB directly labeled with fluorescent dyes to localize these myosin-II isozymes in HeLa cells, melanoma cells and blood cells. Both antibodies react strongly with myosin-II isozymes in HeLa cells, melanoma cells and blood eosinophils, but only anti-myosin-IIA antibodies stain platelets, lymphocytes, neutrophils and monocytes in smears of human blood. Both antibodies stain small spots along the stress fibers of interphase HeLa cells and melanoma cells, but double staining revealed that the detailed distributions of myosin-IIA and myosin-IIB differ. A low concentration of diffuse myosin-IIB is present in the cortex, both in lamellar regions around the periphery of the cell and over the free surface. Myosin-IIB is also concentrated in spots along perinuclear stress fibers. Myosin-IIA is absent from the cortex but is concentrated in spots along stress fibers located near the basal surface of cultured cells. This population of peripheral stress fibers is highly enriched in myosin-IIA relative to myosin-IIB, but both are found together in centrally located stress fibers. In prophase and metaphase both isozymes are concentrated in the cortex in small spots less than 04.micron in size, similar to those in stress fibers. As the chromosomes begin the separate at anaphase, most of the myosin-II spots become concentrated in the outer 0.7 micron of the equatorial cortex in 100% of cells. This concentration of myosin-II isozymes in the cleavage furrow is maintained until the daughter cells separate. The superimposition of these small spots concentrated in the cleavage furrow produces the intense, uniform staining observed in conventional micrographs of whole cells.
Collapse
|
|
31 |
193 |
17
|
Phillips C, Pellathy T, Marantz A, Yellin E, Wexler K, Poeppel D, McGinnis M, Roberts T. Auditory cortex accesses phonological categories: an MEG mismatch study. J Cogn Neurosci 2000; 12:1038-55. [PMID: 11177423 DOI: 10.1162/08989290051137567] [Citation(s) in RCA: 184] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The studies presented here use an adapted oddball paradigm to show evidence that representations of discrete phonological categories are available to the human auditory cortex. Brain activity was recorded using a 37-channel biomagnetometer while eight subjects listened passively to synthetic speech sounds. In the phonological condition, which contrasted stimuli from an acoustic /dae/-/tae/ continuum, a magnetic mismatch field (MMF) was elicited in a sequence of stimuli in which phonological categories occurred in a many-to-one ratio, but no acoustic many-to-one ratio was present. In order to isolate the contribution of phonological categories to the MMF responses, the acoustic parameter of voice onset time, which distinguished standard and deviant stimuli, was also varied within the standard and deviant categories. No MMF was elicited in the acoustic condition, in which the acoustic distribution of stimuli was identical to the first experiment, but the many-to-one distribution of phonological categories was removed. The design of these studies makes it possible to demonstrate the all-or-nothing property of phonological category membership. This approach contrasts with a number of previous studies of phonetic perception using the mismatch paradigm, which have demonstrated the graded property of enhanced acoustic discrimination at or near phonetic category boundaries.
Collapse
|
Clinical Trial |
25 |
184 |
18
|
Mor V, Branco K, Fleishman J, Hawes C, Phillips C, Morris J, Fries B. The structure of social engagement among nursing home residents. J Gerontol B Psychol Sci Soc Sci 1995; 50:P1-P8. [PMID: 7757818 DOI: 10.1093/geronb/50b.1.p1] [Citation(s) in RCA: 182] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
This research tests the reliability and construct validity of social engagement, a new quality of life measure embedded in the federally mandated Resident Assessment Instrument (RAI) for the nursing home population. The sample consisted of 1,848 residents from 268 homes in 10 states with data collected by trained research nurses. Three resident groups were formed based on residents' cognitive and ADL functioning. Social engagement was significantly related to average time spent in activities across all three groups. We hypothesized a four-factor model with social engagement distinct from mood problems, conflicted relationships, and behavior problems. LISREL confirmatory factor analysis found the data to be consistent with this hypothesis (Fit Index > .98). Intercorrelations between factors showed that for high-functioning residents, engagement was negatively related to conflict but was positively related to conflict among the most impaired. The validity of the social engagement measure and its stability across types of residents suggest its potential utility as a marker of nursing home quality.
Collapse
|
|
30 |
182 |
19
|
Ferrucci L, Izmirlian G, Leveille S, Phillips CL, Corti MC, Brock DB, Guralnik JM. Smoking, physical activity, and active life expectancy. Am J Epidemiol 1999; 149:645-53. [PMID: 10192312 DOI: 10.1093/oxfordjournals.aje.a009865] [Citation(s) in RCA: 176] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The effect of smoking and physical activity on active and disabled life expectancy was estimated using data from the Established Populations for Epidemiologic Studies of the Elderly (EPESE). Population-based samples of persons aged > or = 65 years from the East Boston, Massachusetts, New Haven, Connecticut, and Iowa sites of the EPESE were assessed at baseline between 1981 and 1983 and followed for mortality and disability over six annual follow-ups. A total of 8,604 persons without disability at baseline were classified as "ever" or "never" smokers and doing "low," "moderate," or "high" level physical activity. Active and disabled life expectancies were estimated using a Markov chain model. Compared with smokers, men and women nonsmokers survived 1.6-3.9 and 1.6-3.6 years longer, respectively, depending on level of physical activity. When smokers were disabled and close to death, most nonsmokers were still nondisabled. Physical activity, from low to moderate to high, was significantly associated with more years of life expectancy in both smokers (9.5, 10.5, 12.9 years in men and 11.1, 12.6, 15.3 years in women at age 65) and nonsmokers (11.0, 14.4, 16.2 years in men and 12.7, 16.2, 18.4 years in women at age 65). Higher physical activity was associated with fewer years of disability prior to death. These findings provide strong and explicit evidence that refraining from smoking and doing regular physical activity predict a long and healthy life.
Collapse
|
Comparative Study |
26 |
176 |
20
|
Morris JN, Nonemaker S, Murphy K, Hawes C, Fries BE, Mor V, Phillips C. A commitment to change: revision of HCFA's RAI. J Am Geriatr Soc 1997; 45:1011-6. [PMID: 9256856 DOI: 10.1111/j.1532-5415.1997.tb02974.x] [Citation(s) in RCA: 173] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To describe the reliability of new assessment items and their clinical utility as judged by experienced nurse assessors, based on the results from the field test of Version 2.0 of the Resident Assessment Instrument (RAI). DESIGN Independent dual assessment of residents of nursing facilities by staff nurses using a draft of Version 2.0 of the minimum data set (MDS). SETTING AND PARTICIPANTS A total of 187 randomly selected residents from 21 nursing homes in seven states volunteered to test Version 2.0 of the MDS. MEASUREMENT The full array of MDS assessment items included measures in the following areas: Background information, cognitive patterns, communication/hearing, vision, mood and behavior, psychosocial well-being, physical functioning and structural problems, continence, disease diagnoses, health condition, oral/nutritional status, dental status, skin condition, activity pursuit patterns, medications, special treatments and procedures, and discharge potential and overall status. RESULTS Evaluative data address issues of MDS item utility and reliability. For new items, almost all achieved a reasonably high-weighted Kappa interrater reliability; revised items also surpassed earlier items, and with the updated training materials, even the non-changed items had higher average reliability levels. Based on the success of the field test and the positive response of the industry, Version 2.0 of the RAI has been adopted, and HCFA has initiated a more long-range process to update further the RAI when necessary. CONCLUSION Findings support the reliability and clinical utility of the new and revised assessment items incorporated by HCFA in Version 2.0 of the MDS.
Collapse
|
|
28 |
173 |
21
|
Tulloch JF, Phillips C, Koch G, Proffit WR. The effect of early intervention on skeletal pattern in Class II malocclusion: a randomized clinical trial. Am J Orthod Dentofacial Orthop 1997; 111:391-400. [PMID: 9109584 DOI: 10.1016/s0889-5406(97)80021-2] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Early treatment for Class II malocclusion is frequently undertaken with the objective of correcting skeletal disproportion by altering the growth pattern. Because the majority of previous studies of growth modification for Class II malocclusion have been based on retrospective record reviews, the efficacy of such an approach has not been well established. In this controlled clinical trial, patients in the mixed dentition with overjet > or = 7 mm were randomly assigned to either early treatment with headgear, or modified bionator, or to observation. All patients were observed for 15 months with no other appliances used during this phase of the trial. The three groups, who were equivalent initially, experienced statistically significant differences (p < 0.01) in skeletal change. There was considerable variation in the pattern of change within all three groups, with about 80% of the treated children responding favorably. Although patients in both early treatment groups had approximately the same reduction in Class II severity, as reflected by change in the ANB angle, the mechanism of this change was different. The headgear group showed restricted forward movement of the maxilla, and the functional appliance group showed a greater increase in mandibular length. The permanence of these skeletal changes and their impact on the subsequent treatment remains to be evaluated.
Collapse
|
Clinical Trial |
28 |
168 |
22
|
Salive ME, Cornoni-Huntley J, Guralnik JM, Phillips CL, Wallace RB, Ostfeld AM, Cohen HJ. Anemia and hemoglobin levels in older persons: relationship with age, gender, and health status. J Am Geriatr Soc 1992; 40:489-96. [PMID: 1634703 DOI: 10.1111/j.1532-5415.1992.tb02017.x] [Citation(s) in RCA: 166] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE To determine the relationship of hemoglobin levels and anemia with age and health status in older adults. DESIGN Survey. SETTING Community. PARTICIPANTS AND METHODS Hematologic tests were obtained from 3,946 adults aged greater than or equal to 71 years in three communities (East Boston, MA; Iowa and Washington counties, IA; and New Haven, CT). RESULTS Hemoglobin level was inversely associated with age, although this was more pronounced in men than in women. The proportion anemic was equal for men and women aged 71-74 years (8.6%) and increased differentially with age, reaching 41% and 21% for men and women aged greater than or equal to 90 years, respectively. Hemoglobin and anemia were independently associated with age, race, body-mass index, smoking, cancer, hospitalization, renal insufficiency, and hypoalbuminemia. The adjusted relative odds of anemia for a 5-year increase in age was 1.5 (95% confidence interval [CI] 1.3-1.8) for men and 1.2 (95% CI 1.1-1.4) for women. CONCLUSIONS Age is significantly associated with both hemoglobin levels and anemia, with a stronger effect in men compared with women, even after simultaneously adjusting for demographic characteristics and health status. The decline of hemoglobin and concomitant increased anemia with age is not necessarily a result of "normal aging" so the detection of anemia in an older person should prompt appropriate clinical attention.
Collapse
|
|
33 |
166 |
23
|
Pignone M, Phillips C, Mulrow C. Use of lipid lowering drugs for primary prevention of coronary heart disease: meta-analysis of randomised trials. BMJ (CLINICAL RESEARCH ED.) 2000; 321:983-6. [PMID: 11039962 PMCID: PMC27504 DOI: 10.1136/bmj.321.7267.983] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To summarise the effect of primary prevention with lipid lowering drugs on coronary heart disease events, coronary heart disease mortality, and all cause mortality. DESIGN Meta-analysis. IDENTIFICATION Systematic search of the Medline database from January 1994 to June 1999 for English language studies examining drug treatment for lipid disorders (use of the MeSH terms "hyperlipidemia" and "anticholesteremic agents," keyword searches for individual drug names, and a search strategy for identifying randomised trials to capture relevant articles); identification of older studies through systematic reviews and hand search of bibliographies. INCLUSION CRITERIA All randomised trials of at least one year's duration that examined drug treatment for patients with no known coronary heart disease, cerebrovascular disease, or peripheral vascular disease and that measured clinical end points, including all cause mortality, coronary heart disease mortality, and non-fatal myocardial infarctions. DATA EXTRACTION Review of the articles and extracted relevant data by two authors separately, with disagreements resolved by consensus. RESULTS Four studies met eligibility criteria. Drug treatment reduced the odds of a coronary heart disease event by 30% (summary odds ratio 0.70, 95% confidence interval 0.62 to 0.79) but not the odds of all cause mortality (0.94, 0.81 to 1.09). When statin drugs were considered alone, no substantial differences in results were found. CONCLUSIONS Treatment with lipid lowering drugs lasting five to seven years reduces coronary heart disease events but not all cause mortality in people with no known cardiovascular disease.
Collapse
|
Meta-Analysis |
25 |
166 |
24
|
Dalton BC, Orstavik D, Phillips C, Pettiette M, Trope M. Bacterial reduction with nickel-titanium rotary instrumentation. J Endod 1998; 24:763-7. [PMID: 9855830 DOI: 10.1016/s0099-2399(98)80170-2] [Citation(s) in RCA: 161] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The purpose of this study was to compare intracanal bacterial reduction on teeth instrumented with 0.04 tapered nickel-titanium (NiTi) rotary instrumentation to bacterial reduction when using a stainless-steel K-file step-back technique using sterile saline irrigation. Forty-eight patients with apical periodontitis were randomly assigned treatment type. The canals were sampled before, during, and after instrumentation. The samples were incubated anaerobically for 7 days at 37 degrees C, colony-forming unit numbers calculated, and a log transformation performed to normalize the counts. Teeth exhibiting apical periodontitis were uniformly infected, whereas vital control teeth were not. A similar and uniform reduction occurred with progressive filing, regardless of technique (p < 0.0001). There was no detectable difference in colony-forming unit count after NiTi rotary or stainless-steel hand instrumentation (p = 0.42). Neither technique could predictably render canals free of bacteria. The results of this study indicate NiTi rotary and stainless-steel hand K-file step-back instrumentation techniques were not significantly different in their ability to reduce intracanal bacteria.
Collapse
|
Clinical Trial |
27 |
161 |
25
|
Warren JL, Bacon WE, Harris T, McBean AM, Foley DJ, Phillips C. The burden and outcomes associated with dehydration among US elderly, 1991. Am J Public Health 1994; 84:1265-9. [PMID: 8059883 PMCID: PMC1615468 DOI: 10.2105/ajph.84.8.1265] [Citation(s) in RCA: 158] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVES Dehydration has been underappreciated as a cause of hospitalization and increased hospital-associated mortality in older people. This study used national data to analyze the burden and outcomes following hospitalizations with dehydration in the elderly. METHODS Data from 1991 Medicare files were used to calculate rates of hospitalization with dehydration, to examine demographic characteristics and concomitant diagnoses associated with dehydration, and to analyze the contribution of dehydration to mortality. RESULTS In 1991, 6.7% (731,695) of Medicare hospitalizations had dehydration listed as one of the five reported diagnoses, a rate of 236.2/10,000 elderly Medicare beneficiaries. In 1991, Medicare reimbursed over $446 million for hospitalizations with dehydration as the principal diagnosis. Older people, men, and Blacks had elevated risks for hospitalization with dehydration. Acute infections, such as pneumonia and urinary tract infections, were frequent concomitant diagnoses. About 50% of elderly Medicare beneficiaries hospitalized with dehydration died within a year of admission. CONCLUSIONS Hospitalization of elderly people with dehydration is a serious and costly medical problem. Attention should be focused on understanding predisposing factors and devising strategies for prevention.
Collapse
|
research-article |
31 |
158 |