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1.
S Afr J Surg ; 62(2): 23-27, 2024 May.
Article in English | MEDLINE | ID: mdl-38838115

ABSTRACT

BACKGROUND: Hepatic inflammatory myofibroblastic tumours (HIMTs) are rare and poorly described in the literature. Most publications are single patient case reports and lack detailed reporting on characteristics, management, and outcomes. This systematic review aimed to assess the demography, clinical presentation, typical imaging features, histopathology, treatment, and outcomes of patients presenting with HIMTs. METHODS: A systematic literature search was performed in MEDLINE (PubMed), EMBASE (Scopus), JSTOR, Cochrane CENTRAL (Cochrane Library), and the databases included in the Web of Science for studies published between 1940 and 2023 on HIMTs, including its reported synonyms. Case series or cohort studies that reported on the management and outcomes of at least four patients with histologically confirmed HIMTs were included in the analysis. RESULTS: After screening 4553 publications, 22 articles including a total of 440 patients with confirmed HIMTs were eligible for inclusion. The average age was 53.4 years (range 42.0-65.0) with a male to female ratio of 1.7:1. Abdominal pain, discomfort, fever, and loss of weight were the most common presenting symptoms. Surgical resection is the standard of care for HIMTs and is associated with low mortality of 3.4% and low disease recurrence. CONCLUSION: HIMT is a disease more often affecting middle-aged males. The lesions are typically solitary with low recurrence after treatment. The relative roles of surgical versus medical treatment remain unclear. Differences in clinical presentation, histopathology, and treatment of HIMTs compared to inflammatory myofibroblastic tumour (IMT) at extrahepatic sites could challenge the current view of IMT as a single pathological entity.


Subject(s)
Liver Neoplasms , Humans , Liver Neoplasms/pathology , Liver Neoplasms/therapy , Liver Neoplasms/surgery , Granuloma, Plasma Cell/surgery , Granuloma, Plasma Cell/pathology , Granuloma, Plasma Cell/diagnosis , Male , Neoplasms, Muscle Tissue/surgery , Neoplasms, Muscle Tissue/pathology , Neoplasms, Muscle Tissue/diagnosis , Female , Middle Aged
2.
J Geophys Res Space Phys ; 127(6): e2022JA030358, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35860435

ABSTRACT

Ground-based very low frequency (VLF) transmitters located around the world generate signals that leak through the bottom side of the ionosphere in the form of whistler mode waves. Wave and particle measurements on satellites have observed that these man-made VLF waves can be strong enough to scatter trapped energetic electrons into low pitch angle orbits, causing loss by absorption in the lower atmosphere. This precipitation loss process is greatly enhanced by intentional amplification of the whistler waves using a newly discovered process called rocket exhaust driven amplification (REDA). Satellite measurements of REDA have shown between 30 and 50 dB intensification of VLF waves in space using a 60 s burn of the 150 g/s thruster on the Cygnus satellite that services the International Space Station. This controlled amplification process is adequate to deplete the energetic particle population on the affected field lines in a few minutes rather than the multi-day period it would take naturally. Numerical simulations of the pitch angle diffusion for radiation belt particles use the UCLA quasi-linear Fokker Planck model to assess the impact of REDA on radiation belt remediation of newly injected energetic electrons. The simulated precipitation fluxes of energetic electrons are applied to models of D-region electron density and bremsstrahlung X-rays for predictions of the modified environment that can be observed with satellite and ground-based sensors.

3.
Rev Sci Instrum ; 88(7): 073507, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28764511

ABSTRACT

Measurement of ionospheric plasma is often performed by a single in situ device or remotely using cameras and radar. This article describes a small, low-resource, deployed spacecraft used as part of a local, multipoint measurement network. A B-field aligned sounding rocket ejects four of these spin-stabilized spacecraft in a cross pattern. In this application, each spacecraft carries two retarding potential analyzers which are used to determine plasma density, flow, and ion temperature. An inertial measurement unit and a light-emitting diode array are used to determine the position and orientation of the devices after deployment. The design of this spacecraft is first described, and then results from a recent test flight are discussed. This flight demonstrated the successful operation of the deployment mechanism and telemetry systems, provided some preliminary plasma measurements in a simple mid-latitude environment, and revealed several design issues.

4.
Geophys Res Lett ; 42(10): 3639-3646, 2015 May 28.
Article in English | MEDLINE | ID: mdl-26709318

ABSTRACT

We introduce and analyze the first data from an array of closely spaced Global Positioning System (GPS) scintillation receivers established in the auroral zone in late 2013 to measure spatial and temporal variations in L band signals at 100-1000 m and subsecond scales. The seven receivers of the Scintillation Auroral GPS Array (SAGA) are sited at Poker Flat Research Range, Alaska. The receivers produce 100 s scintillation indices and 100 Hz carrier phase and raw in-phase and quadrature-phase samples. SAGA is the largest existing array with baseline lengths of the ionospheric diffractive Fresnel scale at L band. With an initial array of five receivers, we identify a period of simultaneous amplitude and phase scintillation. We compare SAGA power and phase data with collocated 630.0 nm all-sky images of an auroral arc and incoherent scatter radar electron precipitation measurements, to illustrate how SAGA can be used in multi-instrument observations for subkilometer-scale studies. KEY POINTS: A seven-receiver Scintillation Auroral GPS Array (SAGA) is now at Poker Flat, Alaska SAGA is the largest subkilometer array to enable phase/irregularities studies Simultaneous scintillation, auroral arc, and electron precipitation are observed.

5.
Biomed Sci Instrum ; 45: 125-30, 2009.
Article in English | MEDLINE | ID: mdl-19369751

ABSTRACT

Traumatic Brain Injury is hypothesized to occur as a function of the strain and strain rate experienced by neural tissues during a traumatic event. In vitro studies of TBI at the cellular level have used a variety of methods to subject neural cell cultures to potentially injurious strains and strain rates. The Advanced Cell Deformation System (ACDS) has been developed which has the ability to independently control strain and strain rate and can strain cell cultures grown on a stretchable membrane from 0.1 to 0.60 at rates up to 25 s-1. The ability to control strain and strain rate independently or to simulate quick repetitive loading was not available in previous devices. Here we present the experiments testing the ability of the ACDS to replicate the results of in vitro experiments of neural cell deformation conducted by earlier researchers. This is a first step toward future experiments which will use the more advanced capabilities of the ACDS.

7.
Brain ; 131(Pt 7): 1736-48, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18567922

ABSTRACT

The pathological correlate of clinical disability and progression in multiple sclerosis is neuronal and axonal loss; however, the underlying mechanisms are unknown. Abnormal phosphorylation of tau is a common feature of some neurodegenerative disorders, such as Alzheimer's disease. We investigated the presence of tau hyperphosphorylation and its relationship with neuronal and axonal loss in chronic experimental autoimmune encephalomyelitis (CEAE) and in brain samples from patients with secondary progressive multiple sclerosis. We report the novel finding of abnormal tau phosphorylation in CEAE. We further show that accumulation of insoluble tau is associated with both neuronal and axonal loss that correlates with progression from relapsing-remitting to chronic stages of EAE. Significantly, analysis of secondary progressive multiple sclerosis brain tissue also revealed abnormally phosphorylated tau and the formation of insoluble tau. Together, these observations provide the first evidence implicating abnormal tau in the neurodegenerative phase of tissue injury in experimental and human demyelinating disease.


Subject(s)
Axons/pathology , Brain/metabolism , Encephalomyelitis, Autoimmune, Experimental/metabolism , Multiple Sclerosis, Chronic Progressive/metabolism , Neurons/pathology , tau Proteins/metabolism , Animals , Blotting, Western/methods , Brain/pathology , Cell Death , Disease Models, Animal , Encephalomyelitis, Autoimmune, Experimental/pathology , Humans , Mice , Mice, Biozzi , Mice, Inbred Strains , Multiple Sclerosis, Chronic Progressive/pathology , Phosphorylation , tau Proteins/physiology
8.
Neuroscience ; 154(3): 885-97, 2008 Jun 26.
Article in English | MEDLINE | ID: mdl-18511204

ABSTRACT

Dopaminergic innervation of the frontal cortex in adults is important for a variety of cognitive functions and behavioral control. However, the role of frontal cortical dopaminergic innervation for neurobehavioral development has received little attention. In the current study, rats were given dopaminergic lesions in the frontal cortex with local micro-infusions of 6-hydroxydopamine (6-OHDA) at 1 week of age. The long-term behavioral effects of neonatal frontal cortical 6-OHDA lesions were assessed in a series of tests of locomotor activity, spatial learning and memory, and i.v. nicotine self-administration. In addition, neurochemical indices were assessed with tissue homogenization and HPLC in the frontal cortex, striatum, and nucleus accumbens of neonatal and adult rats after neonatal 6-OHDA lesions. In neonatal rats, frontal 6-OHDA lesions as intended caused a significant reduction in frontal cortical dopamine without effects on frontal cortical 5-HT and norepinephrine. The frontal cortical dopamine depletion increased 5-HT and norepinephrine levels in the nucleus accumbens. Locomotor activity assessment during adulthood in the figure-8 maze showed that lesioned male rats were hyperactive relative to sham-lesioned males. Locomotor activity of female rats was not significantly affected by the neonatal frontal 6-OHDA lesion. Learning and memory in the radial-arm maze was also affected by neonatal frontal 6-OHDA lesions. There was a general trend toward impaired performance in early maze acquisition and a paradoxical improvement at the end of cognitive testing. Nicotine self-administration showed significant lesion x sex interactions. The sex difference in nicotine self-administration with females self-administering significantly more nicotine than males was reversed by neonatal 6-OHDA frontal cortical lesions. Neurochemical studies in adult rats showed that frontal cortical dopamine and DOPAC levels significantly correlated with nicotine self-administration in the 6-OHDA-lesioned animals but not in the controls. Frontal cortical 5-HT and 5HIAA showed inverse correlations with nicotine self-administration in the 6-OHDA-lesioned animals but not in the controls. These results show that interfering with normal dopamine innervation of the frontal cortex during early postnatal development has persisting behavioral effects, which are sex-specific.


Subject(s)
Learning/drug effects , Motor Activity/drug effects , Nicotine/pharmacology , Nicotinic Agonists/pharmacology , Oxidopamine , Prefrontal Cortex/physiology , Sympathectomy, Chemical , Sympatholytics , Tobacco Use Disorder/psychology , Animals , Animals, Newborn , Brain Chemistry/drug effects , Chromatography, High Pressure Liquid , Dopamine/physiology , Female , Male , Maze Learning/drug effects , Memory/drug effects , Nicotine/administration & dosage , Nicotinic Agonists/administration & dosage , Norepinephrine/metabolism , Rats , Rats, Sprague-Dawley , Self Administration , Serotonin/metabolism
9.
Science ; 311(5766): 1453-5, 2006 Mar 10.
Article in English | MEDLINE | ID: mdl-16456037

ABSTRACT

We report the direct detection of solid water ice deposits exposed on the surface of comet 9P/Tempel 1, as observed by the Deep Impact mission. Three anomalously colored areas are shown to include water ice on the basis of their near-infrared spectra, which include diagnostic water ice absorptions at wavelengths of 1.5 and 2.0 micrometers. These absorptions are well modeled as a mixture of nearby non-ice regions and 3 to 6% water ice particles 10 to 50 micrometers in diameter. These particle sizes are larger than those ejected during the impact experiment, which suggests that the surface deposits are loose aggregates. The total area of exposed water ice is substantially less than that required to support the observed ambient outgassing from the comet, which likely has additional source regions below the surface.


Subject(s)
Ice/analysis , Meteoroids , Spectrophotometry, Infrared
10.
Science ; 310(5746): 258-64, 2005 Oct 14.
Article in English | MEDLINE | ID: mdl-16150978

ABSTRACT

Deep Impact collided with comet Tempel 1, excavating a crater controlled by gravity. The comet's outer layer is composed of 1- to 100-micrometer fine particles with negligible strength (<65 pascals). Local gravitational field and average nucleus density (600 kilograms per cubic meter) are estimated from ejecta fallback. Initial ejecta were hot (>1000 kelvins). A large increase in organic material occurred during and after the event, with smaller changes in carbon dioxide relative to water. On approach, the spacecraft observed frequent natural outbursts, a mean radius of 3.0 +/- 0.1 kilometers, smooth and rough terrain, scarps, and impact craters. A thermal map indicates a surface in equilibrium with sunlight.


Subject(s)
Meteoroids , Jupiter , Organic Chemicals/analysis , Spectrum Analysis
11.
Neuroscience ; 127(4): 813-20, 2004.
Article in English | MEDLINE | ID: mdl-15312894

ABSTRACT

The cortical stab injury has been widely used for biochemical analysis of molecular changes following CNS injury. However, the cellular responses to this injury have not been accurately quantified. In order to provide a baseline for biochemical studies and future experiments on the manipulation of the CNS injury response we have undertaken a quantitative analysis of this injury. The proliferative and reactive responses of oligodendrocyte precursor cells, astrocytes and microglia were measured, using antibodies to NG2, glial fibrillary acidic protein (GFAP) and the cd11-b clone OX-42 to characterise these cell types at 2, 4, 7 and 14 days post-injury. Oligodendrocyte precursors and microglia proliferated rapidly during the first week, mostly within 0.3 mm of the lesion. Of the dividing cells over 60% were oligodendrocyte precursor cells with microglia making up the balance of the dividing cells. Minimal numbers of astrocytes divided in response to the lesion. Large cells with one or two short processes that were both NG2 and OX-42 positive were identified very close to the lesion at 2 and 4 days post-lesion but not thereafter. They are likely to be blood-derived cells that express NG2 or have ingested it. NG2 immunohistochemistry and platelet-derived growth factor alpha receptor (PDGFalpha-R) in situ hybridisation on neighbouring sections was performed. In the lesioned area only 12% of NG2 positive (+ive) cells were PDGFalpha-R +ive (a ratio of 1:8 for PDGFalpha-R +ive cells: NG2 +ive cells) compared with 33% in the unlesioned cortex and an almost 100% overlap in the spinal cord.


Subject(s)
Astrocytes/cytology , Cerebral Cortex/cytology , Cerebral Cortex/injuries , Microglia/cytology , Oligodendroglia/cytology , Stem Cells/cytology , Animals , Astrocytes/chemistry , Cell Differentiation/physiology , Cerebral Cortex/chemistry , Glial Fibrillary Acidic Protein/analysis , Microglia/chemistry , Oligodendroglia/chemistry , Rats , Wounds, Penetrating/pathology
12.
Neuroscience ; 127(4): 821-32, 2004.
Article in English | MEDLINE | ID: mdl-15312895

ABSTRACT

The MRL/MpJ mouse has a greatly enhanced healing response and an absence of scarring compared with other mouse strains. Following lesions to the CNS mammals show a scarring response known as reactive gliosis, and this CNS scar tissue blocks regeneration of cut axons. We have therefore compared reactive gliosis in the MRL/MpJ mouse and the Swiss Webster mouse, which exhibits normal scarring in the periphery. The lesion model was a stab lesion to the cortex, in which reactive gliosis has previously been quantified. Axon regeneration was examined following a cut lesion to the dopaminergic projection from the substantia nigra to the striatum used in previous regeneration experiments. In the MRL/MpJ following the lesion compared with Swiss Webster mice there was greater cell loss around the lesion followed by greater and more widespread and more prolonged cellular proliferation. Early after the lesion there was a greater loss of glial fibrillary acidic protein (GFAP)-positive astrocytes around the injury site in the MRL/MpJ, and an enhancement and prolongation of the microglial inflammatory response. This was accompanied by greater and more widespread blood-brain barrier leakage following injury. RNA levels for the matrix metalloproteinases (MMP)-2 and MMP-9 as well as for the thrombin receptors PAR-1 and PAR-4 were also greater at the MRL/MpJ injury site. All of these differences were transient and by 14 days post-injury there were no differences observed between MRL/MpJ and control mice. No axonal regeneration was observed following axotomy to the nigrostriatal pathway of the MRL/MpJ or the Swiss Webster mice at any time point.


Subject(s)
Cerebral Cortex/injuries , Cerebral Cortex/metabolism , Mice, Inbred MRL lpr/physiology , Wound Healing/physiology , Animals , Central Nervous System/injuries , Central Nervous System/metabolism , Female , Glial Fibrillary Acidic Protein/genetics , Glial Fibrillary Acidic Protein/metabolism , Matrix Metalloproteinases/genetics , Matrix Metalloproteinases/metabolism , Mice , Mice, Inbred MRL lpr/genetics , Microglia/metabolism , Species Specificity , Wound Healing/genetics , Wounds, Penetrating/genetics , Wounds, Penetrating/metabolism
14.
Prehosp Disaster Med ; 16(1): 22-5, 2001.
Article in English | MEDLINE | ID: mdl-11367933

ABSTRACT

INTRODUCTION: Disaster is a collective responsibility requiring coordinated response from all parts of society. This theme focused on coordination and management issues in a diverse range of scenarios. METHODS: Details of the methods used are provided in the preceding paper. The chairs moderated all presentations and produced a summary that was presented to an assembly of all of the delegates. Although the main points developed in Themes 1 and 4 were different from each other (as reported in the Results section), their implementation was similar. Therefore, the chairs of both groups presided over one workshop that resulted in the generation of a set of Action Plans that then were reported to the collective group of all delegates. RESULTS: The main points developed during the presentations and discussions included: (1) the need for evidence-based assessments and planning, (2) the need for a shift in focus to health-sector readiness, (3) empowerment of survivors, (4) provision of relief for the caregivers, (5) address the incentives and disincentives to attain readiness, (6) engage in joint preparation, response, and training, (7) focus on prevention and mitigation of the damage from events, and (8) improve media relations. There exists a need for institutionalization of processes for learning from experiences obtained from disasters. DISCUSSION: Action plans presented include: (1) creation of an Information and Data Clearinghouse on Disaster Management, (2) identification of incentives and disincentives for readiness and develop strategies and interventions, and (3) act on lessons learned from evidence-based research and practical experience. CONCLUSIONS: There is an urgent need to proactively establish coordination and management procedures in advance of any crisis. A number of important insights for improvement in coordination and management during disasters emerged.


Subject(s)
Continuity of Patient Care/organization & administration , Disaster Planning/organization & administration , Health Planning/organization & administration , Interinstitutional Relations , Needs Assessment/organization & administration , Relief Work/organization & administration , Databases, Factual , Evidence-Based Medicine , Health Services Research , Humans , Mass Media , Power, Psychological , Primary Prevention/organization & administration , Program Development/methods , Public Relations , Survivors
16.
J Clin Psychopharmacol ; 21(1): 21-6, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11199943

ABSTRACT

Divalproex sodium has been approved for use in treating bipolar disorder. Its usefulness in schizophrenia has yet to be adequately assessed. Three days after initiating haloperidol treatment, patients who were hospitalized for an acute exacerbation of schizophrenia received either valproate augmentation (early-augmentation group) or continued to receive haloperidol alone (no-augmentation group). Patients in the no-augmentation group who failed to respond 14 days after the dose of haloperidol reached 20 mg/day received valproate augmentation (delayed-augmentation group). By day 14, the early-augmentation group improved 32.4% more than the no-augmentation group. Fifty percent of the patients in the no-augmentation group failed to respond to haloperidol alone for 2 weeks. They improved by 29% upon the addition of valproate. Compared with those who received no or delayed augmentation, the early-augmentation group required 44.8% fewer inpatient days from the initiation of haloperidol treatment. Patient response to treatment was particularly noted in suspiciousness, hallucinations, unusual thought content, and emotional withdrawal. Early augmentation with valproate may reduce the length of inpatient stays and provide substantially better therapeutic outcomes. It is, however, premature to recommend changes in the standard clinical management of schizophrenia on the basis of the data provided herein, in view of the small sample and open-label nature of the report.


Subject(s)
Antimanic Agents/therapeutic use , Antipsychotic Agents/therapeutic use , Haloperidol/therapeutic use , Schizophrenia/drug therapy , Valproic Acid/therapeutic use , Adult , Antimanic Agents/economics , Antipsychotic Agents/economics , Drug Therapy, Combination , Female , Haloperidol/economics , Hospitalization/economics , Humans , Male , Schizophrenia/economics , Treatment Outcome , Valproic Acid/economics
17.
Neuroreport ; 11(14): 3199-202, 2000 Sep 28.
Article in English | MEDLINE | ID: mdl-11043548

ABSTRACT

The functional role of Ca2+-permeable non-NMDA receptors in spinal nociceptive processing was investigated using joro spider toxin (JSTx), a selective blocker of these receptors. JSTx 0.25 and 1 microg administered spinally produced a significant facilitation of the C-fibre evoked response and post-discharge, but not the A-fibre response, of dorsal horn neurones recorded in adult rats. This may result from a block of Ca2+-permeable AMPA receptors located on GABAergic interneurones. At higher doses, this facilitation of responses was lost, suggesting additional Ca2+-permeable non-NMDA receptors, possibly kainate receptors, in excitatory spinal pathways. Thus, functional Ca2+-permeable AMPA receptors are present within the dorsal horn, predominantly within inhibitory pathways, and play a role distinct from other excitatory amino acid receptors in spinal nociceptive processing.


Subject(s)
Calcium Channels/metabolism , Nociceptors/metabolism , Pain/physiopathology , Posterior Horn Cells/metabolism , Receptors, AMPA/metabolism , Synaptic Transmission/physiology , Animals , Calcium Channels/drug effects , Dose-Response Relationship, Drug , Glutamic Acid/metabolism , Male , Nerve Fibers/drug effects , Nerve Fibers/metabolism , Nerve Fibers/ultrastructure , Nociceptors/cytology , Nociceptors/drug effects , Pain/pathology , Posterior Horn Cells/cytology , Posterior Horn Cells/drug effects , Rats , Rats, Sprague-Dawley , Receptors, AMPA/drug effects , Spider Venoms/pharmacology , Synaptic Transmission/drug effects
18.
J Acoust Soc Am ; 108(2): 803-12, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10955647

ABSTRACT

Vibrational mode shapes have been studied in several tenor (soprano range) and double-second (alto range) steelpans by three well-known makers. Normal modes are determined from operating deflection shapes recorded by means of electronic TV holography. Vibrational modes of the various note areas are designated by the number of radial and circumferential nodal lines. Tuners generally tune one mode an octave above the fundamental and, if possible, a third mode is tuned either a twelfth or two octaves above the fundamental. Note dimensions follow an approximate scaling law L=Kf(213), and the larger note areas can be roughly modeled as rectangular plates with simply supported edges. Modal shapes in the skirt correspond to standing bending waves propagating around the ring.


Subject(s)
Music , Vibration , Acoustic Stimulation/instrumentation , Humans
19.
Health Mark Q ; 17(4): 77-93, 2000.
Article in English | MEDLINE | ID: mdl-11183662

ABSTRACT

Much has been written regarding the market orientation and professionalism constructs, but there is little work relating the two. Understanding the relationship between a market orientation and professionalism is of great relevance to the development and implementation of marketing programs in professional service organizations. Past research suggests that either a positive or a negative connection between these constructs could exist. However, a survey of certified nurse-midwives finds a fairly strong positive relationship between market orientation and professionalism.


Subject(s)
Marketing of Health Services , Nurse Midwives/organization & administration , Professional Practice , Health Care Sector , Surveys and Questionnaires , United States
20.
J Am Acad Nurse Pract ; 12(6): 218-25, 2000 Jun.
Article in English | MEDLINE | ID: mdl-11930444

ABSTRACT

This article reports the findings of an exploratory study on the level of professionalism among certified-nurse midwives (CNMs). Using a five dimensional scale to measure professionalism, our research examined the level of professionalism among CNMs. It explored the relationship between organizational reward structures, level of education, and professionalism. The results show that CNMs exhibit a high degree of professionalism in the practice of nurse-midwifery. The findings also support the notion of a causal relationship between reward structures, education levels and CNM professionalism.


Subject(s)
Certification , Nurse Midwives/standards , Nursing Audit , Attitude of Health Personnel , Career Mobility , Education, Nursing , Health Care Surveys , Humans , Professional Competence
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