1
|
Lin CL, Bristol LA, Jin L, Dykes-Hoberg M, Crawford T, Clawson L, Rothstein JD. Aberrant RNA processing in a neurodegenerative disease: the cause for absent EAAT2, a glutamate transporter, in amyotrophic lateral sclerosis. Neuron 1998; 20:589-602. [PMID: 9539131 DOI: 10.1016/s0896-6273(00)80997-6] [Citation(s) in RCA: 489] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that is characterized by selective upper and lower motor neuron degeneration, the pathogenesis of which is unknown. About 60%-70% of sporadic ALS patients have a 30%-95% loss of the astroglial glutamate transporter EAAT2 (excitatory amino acid transporter 2) protein in motor cortex and spinal cord. Loss of EAAT2 leads to increased extracellular glutamate and excitotoxic neuronal degeneration. Multiple abnormal EAAT2 mRNAs, including intron-retention and exon-skipping, have now been identified from the affected areas of ALS patients. The aberrant mRNAs were highly abundant and were found only in neuropathologically affected areas of ALS patients but not in other brain regions. They were found in 65% of sporadic ALS patients but were not found in nonneurologic disease or other disease controls. They were also detectable in the cerebrospinal fluid (CSF) of living ALS patients, early in the disease. In vitro expression studies suggest that proteins translated from these aberrant mRNAs may undergo rapid degradation and/ or produce a dominant negative effect on normal EAAT2 resulting in loss of protein and activity. These findings suggest that the loss of EAAT2 in ALS is due to aberrant mRNA and that these aberrant mRNAs could result from RNA processing errors. Aberrant RNA processing could be important in the pathophysiology of neurodegenerative disease and in excitotoxicity. The presence of these mRNA species in ALS CSF may have diagnostic utility.
Collapse
|
|
27 |
489 |
2
|
Marrone DP, Spilker JS, Hayward CC, Vieira JD, Aravena M, Ashby MLN, Bayliss MB, Béthermin M, Brodwin M, Bothwell MS, Carlstrom JE, Chapman SC, Chen CC, Crawford TM, Cunningham DJM, De Breuck C, Fassnacht CD, Gonzalez AH, Greve TR, Hezaveh YD, Lacaille K, Litke KC, Lower S, Ma J, Malkan M, Miller TB, Morningstar WR, Murphy EJ, Narayanan D, Phadke KA, Rotermund KM, Sreevani J, Stalder B, Stark AA, Strandet ML, Tang M, Weiß A. Galaxy growth in a massive halo in the first billion years of cosmic history. Nature 2018; 553:51-54. [PMID: 29211721 DOI: 10.1038/nature24629] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 10/06/2017] [Indexed: 11/09/2022]
Abstract
According to the current understanding of cosmic structure formation, the precursors of the most massive structures in the Universe began to form shortly after the Big Bang, in regions corresponding to the largest fluctuations in the cosmic density field. Observing these structures during their period of active growth and assembly-the first few hundred million years of the Universe-is challenging because it requires surveys that are sensitive enough to detect the distant galaxies that act as signposts for these structures and wide enough to capture the rarest objects. As a result, very few such objects have been detected so far. Here we report observations of a far-infrared-luminous object at redshift 6.900 (less than 800 million years after the Big Bang) that was discovered in a wide-field survey. High-resolution imaging shows it to be a pair of extremely massive star-forming galaxies. The larger is forming stars at a rate of 2,900 solar masses per year, contains 270 billion solar masses of gas and 2.5 billion solar masses of dust, and is more massive than any other known object at a redshift of more than 6. Its rapid star formation is probably triggered by its companion galaxy at a projected separation of 8 kiloparsecs. This merging companion hosts 35 billion solar masses of stars and has a star-formation rate of 540 solar masses per year, but has an order of magnitude less gas and dust than its neighbour and physical conditions akin to those observed in lower-metallicity galaxies in the nearby Universe. These objects suggest the presence of a dark-matter halo with a mass of more than 100 billion solar masses, making it among the rarest dark-matter haloes that should exist in the Universe at this epoch.
Collapse
|
|
7 |
130 |
3
|
Crawford T, Crawford MD. Prevalence and pathological changes of ischaemic heart-disease in a hard-water and in a soft-water area. Lancet 1967; 1:229-32. [PMID: 4163142 DOI: 10.1016/s0140-6736(67)91297-4] [Citation(s) in RCA: 116] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
|
58 |
116 |
4
|
Scott LJ, Griffin JW, Luciano C, Barton NW, Banerjee T, Crawford T, McArthur JC, Tournay A, Schiffmann R. Quantitative analysis of epidermal innervation in Fabry disease. Neurology 1999; 52:1249-54. [PMID: 10214752 DOI: 10.1212/wnl.52.6.1249] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To use skin biopsy specimens to quantitate the cutaneous innervation density of Fabry patients who had preserved renal function. BACKGROUND The small fiber neuropathy of Fabry disease is difficult to detect and quantitate by conventional methods. Because this neuropathy is a common characteristic of Fabry disease, quantitating changes in this parameter would be helpful in demonstrating the effectiveness of enzyme or gene replacement therapy. METHODS Patients underwent skin biopsy at the thigh and foot. Innervation density was determined by counting free nerve endings in the epidermis. These data were compared with nerve conduction studies, and in selected patients, fiber quantitation of sural nerve biopsy specimens. RESULTS The Fabry patients had normal results of nerve conduction studies and large fiber quantitation by sural nerve biopsy. However, the involvement of small cutaneous fibers in these patients was easily demonstrable and quantifiable by skin biopsy. All patients showed severe loss of intraepidermal innervation at the ankle, but fiber loss at the distal thigh was proportionately less severe. CONCLUSIONS The nerve damage in Fabry patients with preserved renal function involves exclusively small myelinated and unmyelinated fibers, and skin biopsy is a useful in detecting and quantitating such damage. Comparison of cutaneous innervation density with quantitation of sural nerve biopsy specimens demonstrated that skin biopsy specimens were as sensitive in detecting the presence of neuropathy as were the nerve specimens. It is speculated that analysis of cutaneous innervation may provide a useful marker of the nervous system's response to specific therapy for Fabry disease.
Collapse
|
|
26 |
98 |
5
|
Thurston SE, Leigh RJ, Crawford T, Thompson A, Kennard C. Two distinct deficits of visual tracking caused by unilateral lesions of cerebral cortex in humans. Ann Neurol 1988; 23:266-73. [PMID: 3377449 DOI: 10.1002/ana.410230309] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We studied horizontal visual tracking in 20 patients with unilateral cerebral lesions and in 10 age-matched control subjects. Five patients, all with posterior lesions, showed impaired smooth pursuit of predictable targets moving toward the side of the cerebral lesion. Using nonpredictable step-ramp stimuli, we identified two distinct deficits of visual tracking. The first was a unidirectional deficit of smooth pursuit, for targets moving toward the side of the lesion, in response to stimuli presented into either visual hemifield. The second deficit, identified in a sixth patient who did not show pursuit asymmetry to predictable targets, was a bidirectional inability to estimate the speed of a moving target in the visual hemifield contralateral to the side of the lesion; this caused inaccurate saccades to moving (but not stationary) targets and impaired smooth pursuit initiation. These visual tracking deficits were independent of homonymous hemianopia or hemispatial neglect. These two tracking deficits are similar to those described in rhesus monkeys with lesions of the medial superior temporal and middle temporal visual areas.
Collapse
|
|
37 |
95 |
6
|
Pegoraro E, Mancias P, Swerdlow SH, Raikow RB, Garcia C, Marks H, Crawford T, Carver V, Di Cianno B, Hoffman EP. Congenital muscular dystrophy with primary laminin alpha2 (merosin) deficiency presenting as inflammatory myopathy. Ann Neurol 1996; 40:782-91. [PMID: 8957020 DOI: 10.1002/ana.410400515] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Ten laminin alpha2-deficient patients were identified by both immunofluorescence and immunoblotting (30% of congenital muscular dystrophy patients tested). Three of the laminin alpha2-deficient patients were carrying a diagnosis of infantile polymyositis prior to immunostaining studies. The clinical features in the 10 merosin-deficient patients were homogeneous, with severe floppiness at birth, delay in achievement of motor milestones, and magnetic resonance imaging findings of white matter changes with normal intelligence. The 10-kb laminin alpha2-coding sequence was screened for causative mutations by reverse transcriptase-polymerase chain reaction/single-stranded conformational polymorphism analysis in muscle biopsy specimens from 5 patients, followed by automatic sequencing of aberrant conformers. Clear loss-of-function deletion mutations were identified in both alleles of 1 patient. Muscle histopathology in this patient showed a striking inflammatory infiltrate of T cells and B cells. Reexamination of biopsy specimens from other laminin alpha2-deficient patients showed minor signs of inflammation in each. Based on these findings and the histological and clinical picture suggesting failure of muscle regeneration, a pathogenesis model for this major subset of congenital muscular dystrophy is proposed. Our data show that muscle histopathology showing a neonatal inflammatory process should be considered consistent with congenital muscular dystrophy.
Collapse
|
Case Reports |
29 |
93 |
7
|
Wyatt LC, Moshnikova A, Crawford T, Engelman DM, Andreev OA, Reshetnyak YK. Peptides of pHLIP family for targeted intracellular and extracellular delivery of cargo molecules to tumors. Proc Natl Acad Sci U S A 2018; 115:E2811-E2818. [PMID: 29507241 PMCID: PMC5866553 DOI: 10.1073/pnas.1715350115] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The pH (low) insertion peptides (pHLIPs) target acidity at the surfaces of cancer cells and show utility in a wide range of applications, including tumor imaging and intracellular delivery of therapeutic agents. Here we report pHLIP constructs that significantly improve the targeted delivery of agents into tumor cells. The investigated constructs include pHLIP bundles (conjugates consisting of two or four pHLIP peptides linked by polyethylene glycol) and Var3 pHLIPs containing either the nonstandard amino acid, γ-carboxyglutamic acid, or a glycine-leucine-leucine motif. The performance of the constructs in vitro and in vivo was compared with previous pHLIP variants. A wide range of experiments was performed on nine constructs including (i) biophysical measurements using steady-state and kinetic fluorescence, circular dichroism, and oriented circular dichroism to study the pH-dependent insertion of pHLIP variants across the membrane lipid bilayer; (ii) cell viability assays to gauge the pH-dependent potency of peptide-toxin constructs by assessing the intracellular delivery of the polar, cell-impermeable cargo molecule amanitin at physiological and low pH (pH 7.4 and 6.0, respectively); and (iii) tumor targeting and biodistribution measurements using fluorophore-peptide conjugates in a breast cancer mouse model. The main principles of the design of pHLIP variants for a range of medical applications are discussed.
Collapse
|
Research Support, N.I.H., Extramural |
7 |
92 |
8
|
Pegoraro E, Marks H, Garcia CA, Crawford T, Mancias P, Connolly AM, Fanin M, Martinello F, Trevisan CP, Angelini C, Stella A, Scavina M, Munk RL, Servidei S, Bönnemann CC, Bertorini T, Acsadi G, Thompson CE, Gagnon D, Hoganson G, Carver V, Zimmerman RA, Hoffman EP. Laminin alpha2 muscular dystrophy: genotype/phenotype studies of 22 patients. Neurology 1998; 51:101-10. [PMID: 9674786 DOI: 10.1212/wnl.51.1.101] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine the number of primary laminin alpha2 gene mutations and to conduct genotype/phenotype correlation in a cohort of laminin alpha2-deficient congenital muscular dystrophy patients. BACKGROUND Congenital muscular dystrophies (CMD) are a heterogeneous group of muscle disorders characterized by early onset muscular dystrophy and a variable involvement of the CNS. Laminin alpha2 deficiency has been reported in about 40 to 50% of cases of the occidental, classic type of CMD. Laminin alpha2 is a muscle specific isoform of laminin localized to the basal lamina of muscle fibers, where it is thought to interact with myofiber membrane receptor, such as integrins, and possibly dystrophin-associated glycoproteins. METHODS Seventy-five CMD patients were tested for laminin alpha2 expression by immunofluorescence and immunoblot. The entire 10 kb laminin alpha2 coding sequence of 22 completely laminin alpha2-deficient patients was screened for causative mutations by reverse transcription (RT)-PCR/single strand conformational polymorphisms (SSCP) analysis and protein truncation test (PTT) analysis followed by automatic sequencing of patient cDNA. Clinical data from the laminin alpha2-deficient patients were collected. RESULTS Thirty laminin alpha2-negative patients were identified (40% of CMD patients tested) and 22 of them were screened for laminin alpha2 mutations. Clinical features of laminin alpha2-deficient patients were similar, with severe floppiness at birth, delay in achievement of motor milestones, and MRI findings of white matter changes with normal intelligence. Loss-of-function mutations were identified in 95% (21/22) of the patients studied. SSCP analysis detected laminin alpha2 gene mutations in about 50% of the mutant chromosomes; PTT successfully identified 75% of the mutations. A two base pair deletion mutation at position 2,096-2,097 bp was present in 23% of the patients analyzed. CONCLUSIONS Our data suggest that the large majority of laminin alpha2-deficient patients show laminin alpha2 gene mutations.
Collapse
|
|
27 |
81 |
9
|
Crawford T, Goodrich S, Henderson L, Kennard C. Predictive responses in Parkinson's disease: manual keypresses and saccadic eye movements to regular stimulus events. J Neurol Neurosurg Psychiatry 1989; 52:1033-42. [PMID: 2795072 PMCID: PMC1031737 DOI: 10.1136/jnnp.52.9.1033] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In a coincidence timing task, Parkinsonian patients and a control group were instructed to synchronize a keypress with the onset of a visual signal which had been preceded by a regular train of warning signals. Although the Parkinsonian group had previously exhibited slower reactions in a conventional simple reaction-time task, they were able to generate predictive responses that fell as close to the target onset as the controls' but showed greater variability. In a second experiment, Parkinsonian patients and controls made saccadic eye movements to a visual target that stepped at regular intervals between two fixed locations. After a few trials all the subjects tended to make predictive saccades that were initiated before the target excursion. However, the Parkinsonian group were slower to develop this strategy and when they did their saccades became considerably more hypometric than those of the controls. Both groups were able to maintain predictive responding even when the visual target disappeared and responses were paced by a buzzer. We concluded that Parkinsonian patients are capable of initiating predictive responses of the eye and the hand, at least in some circumstances, but such responses tend to be inaccurate in execution. This, in turn, may dispose the Parkinsonian patient against predictive movement.
Collapse
|
research-article |
36 |
79 |
10
|
O'Toole D, Li H, Roberts S, Rovnak J, DeMartini J, Cavender J, Williams B, Crawford T. Chronic generalized obliterative arteriopathy in cattle: a sequel to sheep-associated malignant catarrhal fever. J Vet Diagn Invest 1995; 7:108-21. [PMID: 7779945 DOI: 10.1177/104063879500700118] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Malignant catarrhal fever (MCF) in cattle is generally associated with a short clinical course and a high case fatality rate (90-95%). The lesions in cattle that survive acute MCF for a prolonged period or appear to recover have not been documented. In a naturally occurring outbreak of MCF in a herd of beef cattle in Wyoming, 7 of 84 yearling heifers (8.3% of replacement herd) and 2 of 230 cows (0.9% of cow herd) developed clinical signs of pyrexia, mucopurulent discharge, bilateral keratitis, and weight loss following contact with ewes that had lambed 34-62 days earlier. Six of 9 affected cattle were examined postmortem following clinical signs (CS) that developed 2-150 days earlier. Three cattle with CS for < or = 39 days had lesions of regional lymphadenopathy and widespread severe segmental lymphoid arteritis-phlebitis that were typical of acute MCF, and proliferative intimal lesions were present in a small proportion of arteries at days 20 and 39 of CS. By contrast, 3 cattle that survived to 90, 105, and 150 days after clinical onset had distinctive arterial lesions in multiple organs, characterized by proliferative concentric fibrointimal plaques, disrupted inner elastic lamina, focally atrophic tunica media, and vasculitis of variable severity. Immunohistochemical and ultrastructural examination of intimal plaques identified the predominant cellular component to be smooth muscle cells with a contractile phenotype. No viral structures were seen. Serologic studies, using a competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA) that detects antibody to an epitope broadly conserved among isolates of the MCF virus, found that 2 chronically affected cattle were serologically positive between days 42 and 100 of CS, with seroconversion in 1 animal between days 52 and 73 of CS. Seroprevalence was 7.9% in the 76 remaining healthy animals of the replacement heifer herd and 40% (75% in adult sheep and 4% in lambs) in the in-contact sheep flock 77 days after onset of CS in the index case. This episode suggests that, in addition to the common and well recognized acute form of MCF in cattle, this viral infection encompasses a disease spectrum that includes chronic disease and partial to "complete" clinical recovery, and in recovered animals chronic obliterative arteriopathy is the preeminent lesion.
Collapse
|
|
30 |
35 |
11
|
|
|
56 |
32 |
12
|
Carter LM, Crawford TM, Sato T, Furuta T, Choi C, Kim CH, Brown JL, Bolch WE, Zanzonico PB, Lewis JS. PARaDIM: A PHITS-Based Monte Carlo Tool for Internal Dosimetry with Tetrahedral Mesh Computational Phantoms. J Nucl Med 2019; 60:1802-1811. [PMID: 31201251 DOI: 10.2967/jnumed.119.229013] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 05/29/2019] [Indexed: 11/16/2022] Open
Abstract
Mesh-type and voxel-based computational phantoms comprise the current state of the art for internal dose assessment via Monte Carlo simulations but excel in different aspects, with mesh-type phantoms offering advantages over their voxel counterparts in terms of their flexibility and realistic representation of detailed patient- or subject-specific anatomy. We have developed PARaDIM (pronounced "paradigm": Particle and Heavy Ion Transport Code System-Based Application for Radionuclide Dosimetry in Meshes), a freeware application for implementing tetrahedral mesh-type phantoms in absorbed dose calculations. It considers all medically relevant radionuclides, including α, β, γ, positron, and Auger/conversion electron emitters, and handles calculation of mean dose to individual regions, as well as 3-dimensional dose distributions for visualization and analysis in a variety of medical imaging software. This work describes the development of PARaDIM, documents the measures taken to test and validate its performance, and presents examples of its uses. Methods: Human, small-animal, and cell-level dose calculations were performed with PARaDIM and the results compared with those of widely accepted dosimetry programs and literature data. Several tetrahedral phantoms were developed or adapted using computer-aided modeling techniques for these comparisons. Results: For human dose calculations, agreement of PARaDIM with OLINDA 2.0 was good-within 10%-20% for most organs-despite geometric differences among the phantoms tested. Agreement with MIRDcell for cell-level S value calculations was within 5% in most cases. Conclusion: PARaDIM extends the use of Monte Carlo dose calculations to the broader community in nuclear medicine by providing a user-friendly graphical user interface for calculation setup and execution. PARaDIM leverages the enhanced anatomic realism provided by advanced computational reference phantoms or bespoke image-derived phantoms to enable improved assessments of radiation doses in a variety of radiopharmaceutical use cases, research, and preclinical development. PARaDIM can be downloaded freely at www.paradim-dose.org.
Collapse
|
Research Support, Non-U.S. Gov't |
6 |
28 |
13
|
Manning D, Barker-Mill SC, Donovan T, Crawford T. Time-dependent observer errors in pulmonary nodule detection. Br J Radiol 2006; 79:342-6. [PMID: 16585729 DOI: 10.1259/bjr/13453920] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The work was carried out to investigate differences in visual search characteristics between groups of observers with different levels of experience in the task of pulmonary nodule detection in chest radiology and we report here on these differences in respect of time related decisions. Volunteer observers were divided into three groups depending on their level of expertise. There were eight radiologists, eight radiographers and eight novices. Their task was to detect pulmonary nodules in a test bank of 120 digitized posteroanterior (PA) chest radiographs. Five of the eight radiographers were tested twice: once before and once after a 6-month training programme in interpretation of the adult chest radiograph. During each test session the observers' eye movements were tracked. Data on the observers' decisions through Alternate Free Response Operating Characteristic (AFROC) methodology were correlated to their eye-movement and fixation patterns. True negative decisions from all observers were associated with shorter fixation times than false negative decisions. No correct negative decisions were made after fixations exceeding 3 s.
Collapse
|
Research Support, Non-U.S. Gov't |
19 |
27 |
14
|
Mendelsohn R, Dluhy RA, Crawford T, Mantsch HH. Interaction of glycophorin with phosphatidylserine: a Fourier transform infrared investigation. Biochemistry 1984; 23:1498-504. [PMID: 6722103 DOI: 10.1021/bi00302a024] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Glycophorin, from the human erythrocyte membrane, has been isolated in pure form and reconstituted into unilamellar vesicles with bovine brain phosphatidylserine (PS). Fourier transform infrared spectroscopy has been used to monitor the protein conformation as well as the effect of protein on lipid order and melting. Glycophorin, at levels of 1 mol %, nearly abolishes the gel to liquid-crystal phase transition seen in pure PS vesicles between 8 and 16 degrees C by inducing significant disorder into the lipid gel phase. A transition of reduced magnitude remains between 14 and 22 degrees C in the lipid/protein complexes. Evidence is presented for specific interaction of glycophorin with the interfacial region of PS. In general, the effects on lipid melting produced by protein at the 1 mol % level are more pronounced than those noted in a previous study of glycophorin/phosphatidylcholine interactions [ Mendelsohn , R., Dluhy , R. A., Taraschi , T., Cameron, D., & Mantsch , H.H. (1981) Biochemistry 20, 6699-6706]. Two bands are observed for the protein amide I (C = O stretching) mode. A main feature at 1653 cm-1 indicates that the bulk of the secondary structure is random coil or alpha-helical. A weaker shoulder at 1675 cm-1 suggests the occurrence of a small proportion of the beta-sheet form. The results confirm circular dichroism studies of Schulte & Marchesi (1979) [ Schulte , T.H., & Marchesi , V.T. (1979) Biochemistry 18, 275-280]. Fourier transform infrared (FT-IR) studies of a ternary complex of PS/dipalmitoyl-phosphatidylcholine- d62 (DPPC- d62 )/glycophorin indicate that the glycophorin preferentially interacts with the PS component.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
|
41 |
27 |
15
|
Shaunak S, O'Sullivan E, Blunt S, Lawden M, Crawford T, Henderson L, Kennard C. Remembered saccades with variable delay in Parkinson's disease. Mov Disord 1999; 14:80-6. [PMID: 9918348 DOI: 10.1002/1531-8257(199901)14:1<80::aid-mds1014>3.0.co;2-m] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The effect of increasing delay on the metrics of remembered saccades was studied in 10 subjects with mild Parkinson's disease, none of whom was receiving treatment with L-dopa, and nine age-matched control subjects. Delays of 1 msec, 250 msec, 1000 msec, 2500 msec, and 5000 msec were used, and reflexive saccades used as a control condition. Results were analyzed for the gain of the primary saccade and the accuracy of the final eye position (FEP gain). Reflexive saccades were normal in subjects with Parkinson's disease, but remembered saccades showed marked hypometria of primary saccade gain at all delays. FEP gain was unimpaired in Parkinson's disease, and primary saccade gain and FEP gain did not vary as a function of delay. Hypometria of primary saccades is compatible with dysfunction in striato-collicular inhibitory pathways in Parkinson's disease, arising as a functional consequence of dopamine deficiency in the basal ganglia. Maintenance of an accurate FEP gain suggests no deficit in oculomotor spatial working memory in Parkinson's disease, at least at delays of up to 5 sec.
Collapse
|
|
26 |
25 |
16
|
Maury W, Perryman S, Oaks JL, Seid BK, Crawford T, McGuire T, Carpenter S. Localized sequence heterogeneity in the long terminal repeats of in vivo isolates of equine infectious anemia virus. J Virol 1997; 71:4929-37. [PMID: 9188555 PMCID: PMC191723 DOI: 10.1128/jvi.71.7.4929-4937.1997] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The role of in vivo long terminal repeat (LTR) sequence variation of the lentivirus equine infectious anemia virus (EIAV) has not been explored. In this study, we investigated the heterogeneity found in the LTR sequences from seven EIAV-seropositive horses: three horses with clinical disease and four horses without any detectable signs of disease. LTR sequences were targeted in this study because the LTR U3 enhancer region of tissue culture-derived isolates has been identified as one of the few hypervariable regions of the EIAV genome. Furthermore, LTR variation may regulate EIAV expression in vivo. Both intra- and interanimal sequence variations were investigated. The intra-animal variation was low in seropositive, healthy horses (on average 0.44%). Intra-animal variation was consistently higher in clinically ill horses (0.99%), suggesting that greater numbers of quasispecies of EIAV are present when active virus replication is ongoing. Interanimal comparisons of consensus sequences generated from each horse demonstrated that the enhancer region is a hotspot of sequence variation in vivo. Thirty-seven of the 83 nucleotides that compose the U3 enhancer region were variable between the different in vivo-derived LTRs. The remainder of the LTR that was analyzed was more conserved, 8 of 195 nucleotide positions being variable. Results of electrophoretic mobility shift assays demonstrated that some nucleotide substitutions that occurred in the enhancer region eliminated or altered transcription factor binding motifs that are known to be important for EIAV LTR expression. These data suggested that the selective pressures exerted on the EIAV LTR enhancer sequences are different from those exerted on the remainder of the LTR. Our findings are consistent with the possibility that enhancer sequence hypervariability can alter expression of the virus in tissue macrophages and therefore contribute to clinical disease in infected horses.
Collapse
|
research-article |
28 |
24 |
17
|
Hanson D, Hoover S, Crites A, Ade PAR, Aird KA, Austermann JE, Beall JA, Bender AN, Benson BA, Bleem LE, Bock JJ, Carlstrom JE, Chang CL, Chiang HC, Cho HM, Conley A, Crawford TM, de Haan T, Dobbs MA, Everett W, Gallicchio J, Gao J, George EM, Halverson NW, Harrington N, Henning JW, Hilton GC, Holder GP, Holzapfel WL, Hrubes JD, Huang N, Hubmayr J, Irwin KD, Keisler R, Knox L, Lee AT, Leitch E, Li D, Liang C, Luong-Van D, Marsden G, McMahon JJ, Mehl J, Meyer SS, Mocanu L, Montroy TE, Natoli T, Nibarger JP, Novosad V, Padin S, Pryke C, Reichardt CL, Ruhl JE, Saliwanchik BR, Sayre JT, Schaffer KK, Schulz B, Smecher G, Stark AA, Story KT, Tucker C, Vanderlinde K, Vieira JD, Viero MP, Wang G, Yefremenko V, Zahn O, Zemcov M. Detection of B-mode polarization in the cosmic microwave background with data from the South Pole Telescope. PHYSICAL REVIEW LETTERS 2013; 111:141301. [PMID: 24138230 DOI: 10.1103/physrevlett.111.141301] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Indexed: 06/02/2023]
Abstract
Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "B-mode" signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a nonzero correlation at 7.7σ significance. The correlation has an amplitude and scale dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable.
Collapse
|
|
12 |
22 |
18
|
Greathouse DV, Goforth RL, Crawford T, Van Der Wel PC, Killian JA. Optimized aminolysis conditions for cleavage of N-protected hydrophobic peptides from solid-phase resins. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 2001; 57:519-27. [PMID: 11437955 DOI: 10.1034/j.1399-3011.2001.00849.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Solid-phase synthesis and aminolysis cleavage conditions were optimized to obtain N- and C-terminally protected hydrophobic peptides with both high quality and yield. Uncharged 'WALP' peptides, consisting of a central (Leu-Ala)n repeating unit (where n = 5, 10.5 or 11.5) flanked on both sides by Trp 'anchors', and gramicidin A (gA) were synthesized using 9-fluorenylmethoxycarbonyl chemistry from either Wang or Merrifield resins. For WALP peptides, the N-terminal amino acid was capped by coupling N-acetyl- or N-formyl-Ala or -Gly to the peptide/resin or by formylation of the completed peptide/resin with para-nitrophenylformate (p-NPF). N-Terminal acetyl- or formyl-Ala racemized when coupled as an HOBt-ester to the resin-bound peptide, but not when the peptide was formylated with p-NPF. Racemization was avoided at the last step by completing the peptide with acetyl- or formyl-Gly. For both WALP peptides and gA, cleavage conditions using ethanolamine or ethylenediamine were optimized as functions of solvent, time, temperature and resin type. For WALP peptides, maximum yields of highly pure peptide were obtained by cleavage with 20% ethanolamine or ethylenediamine in 80% dichloromethane for 48 h at 24 degrees C. N-Acetyl-protected WALP peptides consistently gave higher yields than those protected with N-formyl. For gA, cleavage with 20% ethanolamine or ethylenediamine in 80% dimethylformamide for 48 h at 24 degrees C gave excellent results. For both WALP peptides and gA, decreasing the cleavage time to 4 h and increasing the temperature to 40-55 degrees C resulted in significantly lower yields. The inclusion of hexafluoroisopropanol in the cleavage solvent mixture did not improve yields for either gA or WALP peptides.
Collapse
|
Comparative Study |
24 |
19 |
19
|
Crawford T, Yoon C, Wolfson K, Beller M, Emerick A, Goldin JG, Aberle DR. The effect of imaging modality on patient management in the evaluation of pulmonary thromboembolism. J Thorac Imaging 2001; 16:163-9. [PMID: 11428415 DOI: 10.1097/00005382-200107000-00004] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A retrospective medical record review was performed to study the differences in clinical risk profiles and the relationships between test results versus management for suspected pulmonary thromboembolism (TE) in patients undergoing either radionuclide ventilation perfusion (V/Q) scans or pulmonary computed tomographic angiography (CTA), as the initial test. Data of 138 consecutive V/Q patients were compared with that of 149 consecutive CTA patients during equivalent 6-month intervals before and after the introduction of CTA. Information on risk factors, signs and symptoms, all diagnostic test results, and the relationships between the test results and ultimate physician management were collected and analyzed. V/Q results predicted physician management in all patients with high probability scans and 91% with normal to low probability scans. There were 35 patients with indeterminate V/Q scans--43% of these patients were managed without any other diagnostic test. CTA results predicted management in all patients with positive studies and 99% of patients with negative studies. In contrast to the V/Q cohort, only seven CTA studies were inconclusive--additional diagnostic tests determined management in all but one case. Compared with V/Q, CTA has fewer indeterminate results, is more directly reflective of management, and reduces the number of patients managed with inconclusive data.
Collapse
|
Comparative Study |
24 |
19 |
20
|
Crawford T, Simonoff E. Parental views about services for children attending schools for the emotionally and behaviourally disturbed (EBD): a qualitative analysis. Child Care Health Dev 2003; 29:481-91. [PMID: 14616906 DOI: 10.1046/j.1365-2214.2003.00368.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIM This study examines the views of parents of children attending schools for the emotionally and behaviourally disturbed (EBD). The study aims to gain an understanding of the journey through the educational system taken by these children and to explore their families' experience of services along the way. METHODS Thirty parents of 25 children attending primary and secondary EBD schools in three South London boroughs took part in focus group discussions. Parents were asked about their experiences of services, including educational, health and social services, as well as how they thought services should be improved. RESULTS Qualitative analysis identified a complex web of individual, professional and organizational factors which contributed to social exclusion of children with EBD problems and their families. These factors included children receiving inadequate education because of long periods of exclusion or inappropriate placements whilst waiting for a statement of special educational needs. Parents also felt personally socially excluded because of lack of childcare provision out of school hours. Many parents felt that their children did not fit into services and were constantly being passed on to other professionals. The analysis identified aspects of services that promote social inclusion and provide support to families, including acceptance of children into EBD schools, help from voluntary organizations and support from other parents with children with EBD problems. Parents particularly stressed the value of working in collaboration with professionals to achieve shared goals. CONCLUSION EBD schools provide a valuable resource for parents. However parents often lack emotional and practical support in coping with their children's complex needs. Agencies need to improve communication and joint working to provide effective services for these families.
Collapse
|
|
22 |
15 |
21
|
|
research-article |
87 |
15 |
22
|
Mc Goldrick EL, Crawford T, Brown JA, Groom KM, Crowther CA. Identifying the barriers and enablers in the implementation of the New Zealand and Australian Antenatal Corticosteroid Clinical Practice Guidelines. BMC Health Serv Res 2016; 16:617. [PMID: 27793150 PMCID: PMC5084422 DOI: 10.1186/s12913-016-1858-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 10/18/2016] [Indexed: 01/22/2023] Open
Abstract
Background The ineffective implementation of evidence based practice guidelines can mean that the best health outcomes are not achieved. This study examined the barriers and enablers to the uptake and implementation of the new bi-national (Australia and New Zealand) antenatal corticosteroid clinical practice guidelines among health professionals, using the Theoretical Domains Framework. Methods Semi-structured interviews or online questionnaires were conducted across four health professional groups and three district health boards in Auckland, New Zealand. The questions were constructed to reflect the 14 behavioural domains from the Theoretical Domains Framework. Relevant domains were identified by the presence of conflicting beliefs within a domain; the frequency of beliefs; and the likely strength of the impact of a belief on the behaviour using thematic analysis. The influence of health professional group and organisation on the different barriers and enablers identified were explored. Results Seventy-three health professionals completed either a semi-structured interview (n = 35) or on-line questionnaire (n = 38). Seven behavioural domains were identified as overarching enablers: belief about consequences; knowledge; social influences; environmental context and resource; belief about capabilities; social professional role and identity; and behavioural regulation. Five behavioural domains were identified as overarching barriers: environmental context and resources; knowledge; social influences; belief about consequences; and social professional role and identity. Differences in beliefs between individual health professional groups were identified within the domains: belief about consequences; social professional role and identity; and emotion. Organisational differences were identified within the domains: belief about consequences; social influences; and belief about capabilities. Conclusion This study has identified some of the enablers and barriers to implementation of the New Zealand and Australian Antenatal Corticosteroid Clinical Practice Guidelines using the validated Theoretical Domains Framework, as perceived by health professionals. We have identified differences between individual health professional groups and organisations. The identification of these behavioural determinants can be used to enhance an implementation strategy, assist in the design of interventions to achieve improved implementation and facilitate process evaluations to understand why or how change interventions are effective. Electronic supplementary material The online version of this article (doi:10.1186/s12913-016-1858-8) contains supplementary material, which is available to authorized users.
Collapse
|
Multicenter Study |
9 |
14 |
23
|
|
|
20 |
12 |
24
|
Covington M, Crawford TM, Parker GJ. Time-resolved measurement of propagating spin waves in ferromagnetic thin films. PHYSICAL REVIEW LETTERS 2002; 89:237202. [PMID: 12485035 DOI: 10.1103/physrevlett.89.237202] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2002] [Indexed: 05/24/2023]
Abstract
We measure the propagation of spatially localized spin waves in NiFe thin films through local inductive detection of the dynamic magnetization. A pulsed magnetic field excites a linear superposition of spin wave modes with a distribution that is predominantly driven by the spatial dependence of the in-plane excitation field. The results of numerical micromagnetic calculations exhibit excellent agreement with experiment and show that a comprehensive account of spatial nonuniformity and propagation is necessary to accurately measure the intrinsic damping rate.
Collapse
|
|
23 |
12 |
25
|
Crawford T. Distribution in cesium chloride gradients of proteoglycans of chick embryo brain and characterization of a large aggregating proteoglycan. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 964:183-92. [PMID: 3342255 DOI: 10.1016/0304-4165(88)90165-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Proteoglycans were extracted from 14-day chick embryo brains, which had been labelled in vitro with [35S]sulfate or 3H-labelled amino acids. 4.0 M guanidinium chloride (containing proteinase inhibitors) extracted 94% of the 35S-labelled glycoconjugates. Following cesium chloride equilibrium centrifugation, the proteoglycans in each fraction were characterized by chromatography on Sepharose CL-2B. The most dense fraction (D1), which contained no detectable non-proteoglycan proteins, contained a large, aggregating chondroitin sulfate proteoglycan in addition to small chondroitin sulfate and heparan sulfate proteoglycans. The less dense fractions (D2-D6) contained both small chondroitin sulfate and heparan sulfate proteoglycans. Removal of hyaluronate from the D1 sample by digestion with Streptomyces hyaluronidase in the presence of proteinase inhibitors showed that aggregation of the large chondroitin sulfate proteoglycan is hyaluronate-dependent. Aggregation was restored by re-addition of hyaluronate. Reduction and alkylation, which blocked aggregation of a cartilage A1 proteoglycan, did not interfere with aggregation of the large brain proteoglycan.
Collapse
|
|
37 |
11 |