1
|
Abstract No. 127 90Y vs. TACE Histopathologic Outcomes in Patients with HCC Who Underwent Orthotopic Liver Transplant: A Single-Center, 7-Year Experience. J Vasc Interv Radiol 2023. [DOI: 10.1016/j.jvir.2022.12.178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023] Open
|
2
|
Publisher's Note: "Neutron emission spectrometer to measure ion temperature on the Fusion Demonstration Plant" [Rev. Sci. Instrum. 93, 113539 (2022)]. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:129904. [PMID: 36586939 DOI: 10.1063/5.0135254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Indexed: 06/17/2023]
|
3
|
Neutron emission spectrometer to measure ion temperature on the Fusion Demonstration Plant. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:113539. [PMID: 36461414 DOI: 10.1063/5.0101814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 10/31/2022] [Indexed: 06/17/2023]
Abstract
General Fusion is building the Fusion Demonstration Plant to demonstrate a magnetized target fusion scheme in which a deuterium plasma is heated from 200 eV to 10 keV by piston-driven compression of a liquid-lithium liner. The multilayer coaxial time-of-flight neutron emission spectrometer is designed to measure the ion temperature near peak compression at which time the neutron yield will approach 1018 neutrons/s. The neutron energy distribution is expected to be Gaussian since the machine uses no neutral beam or radio-frequency heating. In this case, analysis shows that as few as 500 coincidence events should be sufficient to accurately measure the ion temperature. This enables a fast time resolution of 10 µs, which is required to track the rapid change in temperature approaching peak compression. We overcome the challenges of neutron pile-up and event ambiguity with a compact design having two layers of segmented scintillators. The error in the ion temperature measurement is computed as a function of the neutron spectrometer's geometric parameters and used to optimize the design for the case of reaching 10 keV at peak compression.
Collapse
|
4
|
Abstract No. 308 Lung shunt fraction before radiation segmentectomy of very early to early stage HCC. J Vasc Interv Radiol 2022. [DOI: 10.1016/j.jvir.2022.03.389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
|
5
|
Therapeutic potential of stem cell and melatonin on the reduction of CCl4-induced liver fibrosis in experimental mice model. BRAZ J BIOL 2022; 84:e253061. [PMID: 35293541 DOI: 10.1590/1519-6984.253061] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 12/23/2021] [Indexed: 11/21/2022] Open
Abstract
Liver fibrosis is initial stage of any chronic liver disease and its end stage is develops into cirrhosis. Chronic liver diseases are a crucial global health issue and the cause of approximately 2 million deaths per year worldwide. Cirrhosis is currently the 11th most common cause of death globally. Mesenchymal stem cell (MSCs) treatment is the best way to treat acute and chronic liver disease. The aim of this study is to improve the therapeutic potential of MSCs combined with melatonin (MLT) to overcome CCl4-induced liver fibrosis and also investigate the individual impact of melatonin and MSCs against CCl4-induced liver impairment in animal model. Female BALB/c mice were used as CCL4-induced liver fibrotic animal model. Five groups of animal model were made; negative control, Positive control, CCl4+MSCs treated group, CCl4+MLT treated group and CCl4+MSCs+MLT treated group. Cultured MSCs from mice bone marrow were transplanted to CCl4-induced liver injured mice model, individually as well as together with melatonin. Two weeks after MSCs and MLT administration, all groups of mice were sacrificed for examination. Morphological and Histopathological results showed that combined therapy of MSCs+MLT showed substantial beneficial impact on CCl4-induced liver injured model, compared with MSCs and MLT individually. Biochemically, considerable reduction was observed in serum bilirubin and ALT levels of MLT+MSC treated mice, compared to other groups. PCR results shown down-regulation of Bax and up-regulation of Bcl-xl and Albumin, confirm a significant therapeutic effect of MSCs+MLT on CCI4-induced liver fibrosis. From the results, it is concluded that combined therapy of MSCs and MLT show strong therapeutic effect on CCL4-induced liver fibrosis, compared with MSCs and MLT individually.
Collapse
|
6
|
643TiP Open-label, phase II study of ladiratuzumab vedotin (LV) for unresectable locally advanced or metastatic solid tumors. Ann Oncol 2021. [DOI: 10.1016/j.annonc.2021.08.1156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
|
7
|
Abstract No. 567 Prostatic artery embolization in patients with prior prostatitis. J Vasc Interv Radiol 2021. [DOI: 10.1016/j.jvir.2021.03.377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
8
|
Abstract No. 452 Prostatic artery embolization for inpatient and emergent hematuria: a single-system experience. J Vasc Interv Radiol 2021. [DOI: 10.1016/j.jvir.2021.03.261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
9
|
Abstract No. 521 Safety and efficacy of coil embolization of the prostate arteries post-particle embolization for lower urinary tract symptoms. J Vasc Interv Radiol 2021. [DOI: 10.1016/j.jvir.2021.03.330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
10
|
Abstract No. 39 Prostatic artery embolization in patients with recurrent lower urinary tract symptoms following failed transurethral resection of the prostate. J Vasc Interv Radiol 2021. [DOI: 10.1016/j.jvir.2021.03.456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
11
|
|
12
|
The novel Mechanical Ventilator Milano for the COVID-19 pandemic. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2021; 33:037122. [PMID: 33897243 PMCID: PMC8060010 DOI: 10.1063/5.0044445] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 02/14/2021] [Indexed: 06/12/2023]
Abstract
This paper presents the Mechanical Ventilator Milano (MVM), a novel intensive therapy mechanical ventilator designed for rapid, large-scale, low-cost production for the COVID-19 pandemic. Free of moving mechanical parts and requiring only a source of compressed oxygen and medical air to operate, the MVM is designed to support the long-term invasive ventilation often required for COVID-19 patients and operates in pressure-regulated ventilation modes, which minimize the risk of furthering lung trauma. The MVM was extensively tested against ISO standards in the laboratory using a breathing simulator, with good agreement between input and measured breathing parameters and performing correctly in response to fault conditions and stability tests. The MVM has obtained Emergency Use Authorization by U.S. Food and Drug Administration (FDA) for use in healthcare settings during the COVID-19 pandemic and Health Canada Medical Device Authorization for Importation or Sale, under Interim Order for Use in Relation to COVID-19. Following these certifications, mass production is ongoing and distribution is under way in several countries. The MVM was designed, tested, prepared for certification, and mass produced in the space of a few months by a unique collaboration of respiratory healthcare professionals and experimental physicists, working with industrial partners, and is an excellent ventilator candidate for this pandemic anywhere in the world.
Collapse
|
13
|
Comparison of perinatal outcomes for all modes of second stage delivery in obstetric theatres: a retrospective observational study. BJOG 2020; 128:1248-1255. [PMID: 33142034 DOI: 10.1111/1471-0528.16589] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To compare rates of vaginal delivery and adverse outcomes of instrumental delivery trials in obstetric theatre compared to primary emergency full dilation caesarean section. DESIGN Retrospective cohort study. SETTING University teaching hospital. POPULATION Women with singleton, non-anomalous, pregnancy undergoing instrumental delivery trial in obstetric theatre. METHODS Data were collected from consecutive cases during 2014 until 2018 using clinical records. Multivariate regression analysis was used comparing outcomes per first delivery method. MAIN OUTCOME MEASURES Primary outcome was completion of vaginal delivery between all methods of instrumental delivery. Secondary outcome was a composite of immediate perinatal adverse outcomes for instrumental delivery modes and primary full dilation caesarean section. RESULTS From 971 deliveries analysed: ventouse delivery was significantly less likely to achieve vaginal delivery compared with Keilland's forceps delivery (odds ratio [OR] 0.42, 95% CI 0.22-0.79). Once confounding factors were adjusted for, adverse outcome rates were less frequent in the Keilland's forceps group than with primary full dilation caesarean section (OR 0.37, 95% CI 0.16-0.81); however, the receiver operating characteristic curve produced from this model demonstrated a low predictive value (AUC 0.64). CONCLUSIONS Attempting instrumental delivery in delivery suite theatre, as an alternative to primary emergency full dilation caesarean section, is both reasonable and safe. In this study, ventouse delivery performed poorly in comparison with other modes of instrumental delivery. Further research in the form of randomised controlled trials to identify the optimal mode of second stage delivery is paramount. TWEETABLE ABSTRACT Instrumental delivery trials in theatre are safe but use of ventouse was associated with a higher rate of failure.
Collapse
|
14
|
Predicting left ventricular contractile function via Gaussian process emulation in aortic-banded rats. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2020; 378:20190334. [PMID: 32448071 PMCID: PMC7287330 DOI: 10.1098/rsta.2019.0334] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Cardiac contraction is the result of integrated cellular, tissue and organ function. Biophysical in silico cardiac models offer a systematic approach for studying these multi-scale interactions. The computational cost of such models is high, due to their multi-parametric and nonlinear nature. This has so far made it difficult to perform model fitting and prevented global sensitivity analysis (GSA) studies. We propose a machine learning approach based on Gaussian process emulation of model simulations using probabilistic surrogate models, which enables model parameter inference via a Bayesian history matching (HM) technique and GSA on whole-organ mechanics. This framework is applied to model healthy and aortic-banded hypertensive rats, a commonly used animal model of heart failure disease. The obtained probabilistic surrogate models accurately predicted the left ventricular pump function (R2 = 0.92 for ejection fraction). The HM technique allowed us to fit both the control and diseased virtual bi-ventricular rat heart models to magnetic resonance imaging and literature data, with model outputs from the constrained parameter space falling within 2 SD of the respective experimental values. The GSA identified Troponin C and cross-bridge kinetics as key parameters in determining both systolic and diastolic ventricular function. This article is part of the theme issue 'Uncertainty quantification in cardiac and cardiovascular modelling and simulation'.
Collapse
|
15
|
Abstract No. 689 Prostate artery embolization in patients with prior transurethral resection of the prostate: a feasibility study. J Vasc Interv Radiol 2020. [DOI: 10.1016/j.jvir.2019.12.748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|
16
|
3:09 PM Abstract No. 63 Balloon occlusion embolization in prostate artery embolization: a single-center evaluation of procedural metrics and clinical outcomes. J Vasc Interv Radiol 2020. [DOI: 10.1016/j.jvir.2019.12.088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|
17
|
3:36 PM Abstract No. 141 Radioembolization for recurrent hepatocellular carcinoma after liver transplant: a multicenter exploratory analysis. J Vasc Interv Radiol 2020. [DOI: 10.1016/j.jvir.2019.12.174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|
18
|
4:21 PM Abstract No. 71 Radial versus femoral artery access in prostate artery embolization: a multicenter experience in a major health system. J Vasc Interv Radiol 2020. [DOI: 10.1016/j.jvir.2019.12.096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|
19
|
Abstract
Objective: To determine audiology student perceptions of two simulated learning environments (SLE) in paediatric audiology.Design: A one-shot case study design.Study sample: Fifteen audiology students who completed questionnaires after participating in two SLEs, one simulating auditory brainstem response (ABR) assessments of neonates in a hospital ward and one simulating visually reinforced orientation audiometry (VROA) assessments of young children in an audiology clinic.Results: The students responded positively to 11/11 areas of audiometric testing and client interaction in both SLEs, to 7/7 aspects of their interactions with the mannequins in both SLEs, and to 8/8 aspects of their interactions with fellow students playing the role of parent in the ABR SLE and 7/8 of these aspects in the VROA SLE. The students reported low levels of anxiety towards both SLEs but rated the ABR SLE more highly than the VROA SLE in areas of preparedness, effectiveness, realism, pre-SLE training, reinforcement of lecture content, and overall usefulness.Conclusions: The participating students responded positively to almost all aspects of both SLEs. Further research is warranted using research designs capable of determining if these SLEs directly improve student abilities as they transition from academic settings to clinical placements in paediatric audiology.
Collapse
|
20
|
04:12 PM Abstract No. 216 Transarterial chemoembolization with 40-90 micron radiopaque drug-eluting microspheres for treatment of hepatocellular carcinoma. J Vasc Interv Radiol 2019. [DOI: 10.1016/j.jvir.2018.12.273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
|
21
|
|
22
|
Retransmission Avoidance for Reliable Data Delivery in Underwater WSNs. SENSORS 2018; 18:s18010149. [PMID: 29316664 PMCID: PMC5795748 DOI: 10.3390/s18010149] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 12/27/2017] [Accepted: 01/04/2018] [Indexed: 12/01/2022]
Abstract
The energy-efficient and reliable delivery of data packets in resource constraint underwater wireless sensor networks (UWSNs) is one of the key considerations to enhance the network lifetime. The traditional re-transmissions approach consumes the node battery and increases the communication overhead, which results in congestion and affects the reliable data packet delivery in the network. To ensure the reliability and conserve the node battery, in this paper, we propose adaptive forwarding layer multipath power control routing protocol to reduce the energy dissipation, achieve the data reliability and avoid the energy hole problem. In order to achieve the reliability, tree based topology is exploited to direct multiple copies of the data packet towards the surface through cross nodes in the network. The energy dissipation is reduced by a substantial amount with the selection of low noise path between the source and the destination including the information of neighbors of the potential forwarder node. Extensive simulation results show that our proposed work outperforms the compared existing scheme in terms of energy efficiency and packet received ratio (PRR).
Collapse
|
23
|
|
24
|
Hemoglobinuria (Black Water Fever) in severe falciparum malaria – a case report. Int J Infect Dis 2016. [DOI: 10.1016/j.ijid.2016.02.812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
25
|
Improved Measurement of the π→eν Branching Ratio. PHYSICAL REVIEW LETTERS 2015; 115:071801. [PMID: 26317713 DOI: 10.1103/physrevlett.115.071801] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Indexed: 06/04/2023]
Abstract
A new measurement of the branching ratio R_{e/μ}=Γ(π^{+}→e^{+}ν+π^{+}→e^{+}νγ)/Γ(π^{+}→μ^{+}ν+π^{+}→μ^{+}νγ) resulted in R_{e/μ}^{exp}=[1.2344±0.0023(stat)±0.0019(syst)]×10^{-4}. This is in agreement with the standard model prediction and improves the test of electron-muon universality to the level of 0.1%.
Collapse
|
26
|
Abstract
ABSTRACT
Objectives:
To examine the 1999 CAEP/AMUQ research abstracts competition in a scientific fashion, and provide descriptive information about the present and future direction of Canadian emergency medicine (EM) research.
Methods:
Using a standard evaluation form, 3 volunteer CAEP reviewers rated each submitted abstract in blind fashion. The authors of this report then combined abstract review scores with the following data: research topic, province of origin, status of first author (resident or attending physician), number of authors, adherence to submission guidelines, and acceptance status.
Results:
Of 86 abstracts submitted, 80 (93%) originated in Canada. The primary author was a resident in 34 cases (40%), a staff physician in 50 cases (58%) and unspecified in 2 cases (2%). Overall, 77 abstracts (90%) were selected for presentation: 26 (29%) oral, 40 (47%) poster, and 11 (13%) for the Resident Research Competition. The most common topics were clinical care (17%), prehospital care (15%), education/administration (14%), and decision rules (13%). The most common reason for rejection was failure to adhere to submission guidelines.
Conclusions:
Canadian EM research is growing rapidly, as witnessed by the interest in this competition, the publication of these abstracts, and the increased emphasis placed on research at the national meeting. Researchers must adhere to submission guidelines to increase their chances of abstract acceptance. Methods of promoting Canadian EM research are discussed.
Collapse
|
27
|
Dense arrays of micro-needles for recording and electrical stimulation of neural activity in acute brain slices. J Neural Eng 2012; 10:016007. [PMID: 23234809 DOI: 10.1088/1741-2560/10/1/016007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE This paper describes the design, microfabrication, electrical characterization and biological evaluation of a high-density micro-needle array. The array records from and electrically stimulates individual neurons simultaneously in acute slices of brain tissue. APPROACH Acute slices, arguably the closest in-vitro model of the brain, have a damaged surface layer. Since electrophysiological recording methods rely heavily on electrode-cell proximity, this layer significantly attenuates the signal amplitude making the use of traditional planar electrodes unsuitable. To penetrate into the tissue, bypassing the tissue surface, and to record and stimulate neural activity in the healthy interior volume of the slice, an array of 61 micro-needles was fabricated. MAIN RESULTS This device is shown to record extracellular action potentials from individual neurons in acute cortical slices with a signal to noise ratio of up to ∼15:1. Electrical stimulation of individual neurons is achieved with stimulation thresholds of 1.1-2.9 µA. SIGNIFICANCE The novelty of this system is the combination of close needle spacing (60 µm), needle heights of up to 250 µm and small (5-10 µm diameter) electrodes allowing the recording of single unit activity. The array is coupled to a custom-designed readout system forming a powerful electrophysiological tool that permits two-way electrode-cell communication with populations of neurons in acute brain slices.
Collapse
|
28
|
Abstract
The objective of this work is to develop and test a photovoltaic retinal prosthesis for restoring sight to patients blinded by degenerative retinal diseases. A silicon photodiode array for subretinal stimulation has been fabricated by a silicon-integrated-circuit/MEMS process. Each pixel in the two-dimensional array contains three series-connected photodiodes, which photovoltaically convert pulsed near-infrared light into bi-phasic current to stimulate nearby retinal neurons without wired power connections. The device thickness is chosen to be 30 µm to absorb a significant portion of light while still being thin enough for subretinal implantation. Active and return electrodes confine current near each pixel and are sputter coated with iridium oxide to enhance charge injection levels and provide a stable neural interface. Pixels are separated by 5 µm wide trenches to electrically isolate them and to allow nutrient diffusion through the device. Three sizes of pixels (280, 140 and 70 µm) with active electrodes of 80, 40 and 20 µm diameter were fabricated. The turn-on voltages of the one-diode, two-series-connected diode and three-series-connected diode structures are approximately 0.6, 1.2 and 1.8 V, respectively. The measured photo-responsivity per diode at 880 nm wavelength is ∼0.36 A W(-1), at zero voltage bias and scales with the exposed silicon area. For all three pixel sizes, the reverse-bias dark current is sufficiently low (<100 pA) for our application. Pixels of all three sizes reliably elicit retinal responses at safe near-infrared light irradiances, with good acceptance of the photodiode array in the subretinal space. The fabricated device delivers efficient retinal stimulation at safe near-infrared light irradiances without any wired power connections, which greatly simplifies the implantation procedure. Presence of the return electrodes in each pixel helps to localize the current, and thereby improves resolution.
Collapse
|
29
|
Assessment of the rapid diagnostic test Immunoquick+4 malaria for the diagnosis of malaria in Kuwait. Int J Infect Dis 2012. [DOI: 10.1016/j.ijid.2012.05.545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
30
|
Abstract
Photodiode circuits show promise for the development of high-resolution retinal prostheses. While several of these systems have been constructed and some even implanted in humans, existing descriptions of the complex optoelectronic interaction between light, photodiode, and the electrode/electrolyte load are limited. This study examines this interaction in depth with theoretical calculations and experimental measurements. Actively biased photoconductive and passive photovoltaic circuits are investigated, with the photovoltaic circuits consisting of one or more diodes connected in series, and the photoconductive circuits consisting of a single diode in series with a pulsed bias voltage. Circuit behavior and charge injection levels were markedly different for platinum and sputtered iridium-oxide film (SIROF) electrodes. Photovoltaic circuits were able to deliver 0.038 mC/cm(2) (0.75 nC/phase) per photodiode with 50- μm platinum electrodes, and 0.54-mC/cm(2) (11 nC/phase) per photodiode with 50-μ m SIROF electrodes driven with 0.5-ms pulses of light at 25 Hz. The same pulses applied to photoconductive circuits with the same electrodes were able to deliver charge injections as high as 0.38 and 7.6 mC/cm(2) (7.5 and 150 nC/phase), respectively. We demonstrate photovoltaic stimulation of rabbit retina in-vitro, with 0.5-ms pulses of 905-nm light using peak irradiance of 1 mW/mm(2). Based on the experimental data, we derive electrochemical and optical safety limits for pixel density and charge injection in various circuits. While photoconductive circuits offer smaller pixels, photovoltaic systems do not require an external bias voltage. Both classes of circuits show promise for the development of high-resolution optoelectronic retinal prostheses.
Collapse
|
31
|
Retinal receptive fields at single cone resolution and implications for color vision. J Vis 2009. [DOI: 10.1167/9.14.83] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
32
|
Prevalence of Infectious Diseases Among Immigrants Detected in Kuwait. Int J Infect Dis 2008. [DOI: 10.1016/j.ijid.2008.05.1284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
33
|
Host and parasite factors influencing the expression of cutaneous leishmaniasis. CIBA FOUNDATION SYMPOSIUM 2008; 99:174-89. [PMID: 6227463 DOI: 10.1002/9780470720806.ch10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Host and parasite factors influencing the expression of cutaneous leishmaniasis were investigated in two murine models of different leishmanial diseases. The role of B lymphocytes in the uncontrolled disease manifested by BALB/c mice infected with cutaneous leishmaniasis was investigated in animals of this inbred strain depleted of B cells by neonatal administration of anti-mouse mu-chain antisera. Whereas non-depleted control mice developed chronic metastatic infections with both Leishmania tropica and Leishmania mexicana and showed depressed delayed-type hypersensitivity when skin-tested with leishmanial antigens, the mu-suppressed mice controlled their initial lesions while displaying strong antigen-specific delayed-type hypersensitivity. These findings reveal an inverse relationship between humoral and cell-mediated immunity in the expression of chronic leishmaniasis and suggest that B lymphocytes or their products regulate the delayed-type hypersensitivity response to leishmanial infection. In a separate study, healing and chronic strains of Leishmania were compared for their susceptibility to killing by lymphokine-activated mouse peritoneal macrophages. Whereas amastigotes of the healing strains were readily destroyed by these macrophages, amastigotes of two Leishmania strains, previously shown to produce chronic infections in mice, were resistant to killing by the same cells. These findings suggest that the ability of certain leishmanial strains to induce chronic disease may result from their capacity to evade intracellular destruction by activated macrophages.
Collapse
|
34
|
Induction and regulation of host cell-mediated immunity by Toxoplasma gondii. CIBA FOUNDATION SYMPOSIUM 2007; 195:95-104; discussion 104-9. [PMID: 8724832 DOI: 10.1002/9780470514849.ch7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Toxoplasma gondii is a highly infectious intracellular parasite which, if left unchecked by the immune system, rapidly overwhelms its intermediate hosts, as illustrated by the pathogenesis of toxoplasmic encephalitis in patients with AIDS. In order to insure both its host's and consequently its own survival simultaneously, T. gondii induces a potent gamma-interferon (IFN-gamma)-dependent cell-mediated immunity early in infection that controls the replication of the protozoan and facilitates transformation into the dormant cyst stage. The protective IFN-gamma is derived from three sources: natural killer cells; and CD4+ and CD8+ T lymphocytes, which can partially compensate for each other in knockout mice lacking the appropriate major histocompatibility complex-restricting elements. At least two properties of the parasite appear to be responsible for the early induction of these effector cells. The first is a hydrophobic molecule (or group of related molecules) that triggers interleukin 12 (IL-12), tumour necrosis factor alpha and IL-1beta synthesis in macrophages. This response can also promote HIV replication in the same cells. The second is a superantigen activity that drives IFN-gamma-producing Vbeta5+ CD8+ T cells. These potentially lethal responses are later regulated through the triggering of IL-10 and by the induction of anergy in the superantigen-stimulated Vbeta5+ T cell population.
Collapse
|
35
|
Sepsis-induced organ failure is mediated by different pathways in the kidney and liver: acute renal failure is dependent on MyD88 but not renal cell apoptosis. Kidney Int 2006; 69:832-6. [PMID: 16518342 PMCID: PMC2271059 DOI: 10.1038/sj.ki.5000165] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Toll-like receptors (TLRs) are important in sepsis. Myeloid differentiation factor 88 (MyD88) is a key molecule involved in signal transduction by multiple TLRs. The objective of this study was to investigate the contribution of TLR4 and MyD88 to acute renal failure (ARF) induced by polymicrobial sepsis. Liver dysfunction and apoptosis in the spleen contribute to sepsis severity after cecal ligation and puncture (CLP). Therefore, we also investigated liver injury and splenic apoptosis. We used a mouse model of sepsis-induced ARF using CLP to generate polymicrobial sepsis. Despite fluid and antibiotic resuscitation the mice developed multi-organ failure, including ARF, which resembles human sepsis. We investigated the role of the TLR4 receptor by comparing C3H/HeJ mice (which lack TLR4) with C3H/He0UJ normal controls. The role of MyD88 was investigated by comparing MyD88 knockout mice (MyD88(-/-)) with wild-type controls. Following CLP, mice lacking TLR4 and wild-type mice both developed comparable ARF. However, MyD88(-/-) mice did not develop ARF compared to wild-type controls. In contrast, MyD88(-/-) mice developed liver injury comparable to wild type. After CLP, MyD88(-/-) mice had significantly reduced apoptosis in the spleen compared with wild type. Apoptosis was not detected in the kidney of wild-type or MyD88(-/-) mice after CLP. In summary, ARF induced by polymicrobial sepsis is dependent on MyD88, but not TLR4. The absence of MyD88 dissociates ARF from liver injury; liver injury is MyD88-independent. There was MyD88-dependent apoptosis in the spleen, but no apoptosis in the kidney. MyD88 may be a good drug target for some, but not all, organ dysfunctions following sepsis.
Collapse
|
36
|
283: Development of Epidemiological Databases as Standalone Applications. Am J Epidemiol 2005. [DOI: 10.1093/aje/161.supplement_1.s71b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
37
|
590: Fuzzy Logic Implementation in Modeling of Seroprevalence Changes as a Composition of Three Age-Dependent Processes. Am J Epidemiol 2005. [DOI: 10.1093/aje/161.supplement_1.s148a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
38
|
|
39
|
Abstract
Sensory experience typically depends on the ensemble activity of hundreds or thousands of neurons, but little is known about how populations of neurons faithfully encode behaviorally important sensory information. We examined how precisely speed of movement is encoded in the population activity of magnocellular-projecting parasol retinal ganglion cells (RGCs) in macaque monkey retina. Multi-electrode recordings were used to measure the activity of approximately 100 parasol RGCs simultaneously in isolated retinas stimulated with moving bars. To examine how faithfully the retina signals motion, stimulus speed was estimated directly from recorded RGC responses using an optimized algorithm that resembles models of motion sensing in the brain. RGC population activity encoded speed with a precision of approximately 1%. The elementary motion signal was conveyed in approximately 10 ms, comparable to the interspike interval. Temporal structure in spike trains provided more precise speed estimates than time-varying firing rates. Correlated activity between RGCs had little effect on speed estimates. The spatial dispersion of RGC receptive fields along the axis of motion influenced speed estimates more strongly than along the orthogonal direction, as predicted by a simple model based on RGC response time variability and optimal pooling. on and off cells encoded speed with similar and statistically independent variability. Simulation of downstream speed estimation using populations of speed-tuned units showed that peak (winner take all) readout provided more precise speed estimates than centroid (vector average) readout. These findings reveal how faithfully the retinal population code conveys information about stimulus speed and the consequences for motion sensing in the brain.
Collapse
|
40
|
|
41
|
High statistics measurement of the K+-->pi0e+nu (K+e3) branching ratio. PHYSICAL REVIEW LETTERS 2003; 91:261802. [PMID: 14754040 DOI: 10.1103/physrevlett.91.261802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2003] [Indexed: 05/24/2023]
Abstract
E865 at the Brookhaven National Laboratory AGS collected about 70 000 K(+)(e3) events to measure the K(+)(e3) branching ratio relative to the observed K+-->pi(+)pi(0), K+-->pi(0)micro(+)nu, and K+-->pi(+)pi(0)pi(0) decays. The pi(0) in all the decays was detected using the e(+)e(-) pair from pi(0)-->e(+)e(-)gamma decay and no photons were required. Using the 2002 Particle Data Group branching ratios for the normalization decays, we obtain BR(K(+)(e3(gamma)))=(5.13+/-0.02(stat)+/-0.09(syst)+/-0.04(norm))%, where K(+)(e3(gamma)) includes the effect of virtual and real photons. This result is approximately 2.3sigma higher than the current Particle Data Group value. Implications for the V(us) element of the CKM matrix, and the matrix's unitarity are discussed.
Collapse
|
42
|
Modified Giemsa staining for rapid diagnosis of malaria infection. Med Princ Pract 2003; 12:156-9. [PMID: 12766332 DOI: 10.1159/000070751] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2002] [Accepted: 01/11/2003] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES To develop and evaluate a rapid method for the diagnosis of malaria infection by microscopy of stained blood films. SUBJECTS AND METHODS Blood specimens were collected from randomly selected confirmed malaria cases (n = 75) and suspected malaria cases (n = 175). The microscopy was done on each set of blood films stained by modified and the standard Giemsa staining methods. RESULTS All the 75 previously diagnosed malaria cases were confirmed by the microscopy of blood films stained by both methods. Forty-nine (28%) of the 175 cases suspected for malaria infection showed malarial parasites on microscopy of blood films stained by both methods. However, due to homogeneous staining and clearer background of the blood films it was possible to determine the parasite species in 65% of the cases on microscopy of the thick films stained with the modified method compared to only 20% with the standard method. Further, the turnaround time for reporting the microscopy test result was 15-20 and 45-50 min with modified and standard staining methods, respectively. CONCLUSION Our data showed that performance of the modified staining method in detecting malarial parasites was comparable to that of the standard staining method. Moreover, the modified staining method was rapid, easy to use, and reliable.
Collapse
|
43
|
Abstract
OBJECTIVE To detect the incidence of drug-resistant Plasmodium falciparum malaria infection in immigrants and travellers in non-endemic Kuwait. METHODS Over a period of 3 years, July 1995 to September 1998, 1352 malaria patients were enrolled in the study. Of these, 1293 were immigrants from countries where malaria is endemic and 59 were non-immune travellers with a recent history of travel to these countries. The in vitro drug sensitivity was determined in 892 patients. RESULTS In all, 892 of 1352 (66.0%) P. falciparum isolates were successfully cultured in vitro for drug sensitivity and 419 (47.0%) isolates showed in vitro resistance to chloroquine or mefloquine. Fifty-six (13.4%) isolates were resistant to both drugs. Chloroquine resistance was observed in > 70% of the isolates from Africa and India followed by Pakistan (39.9%) and Bangladesh (35.9%). The resistance to mefloquine ranged from 26.2% in isolates from Sri Lanka to 47.5% in isolates from African countries. CONCLUSION The study highlights the important trend in drug resistance in P. falciparum malaria in immigrants from south-east Asian and African countries.
Collapse
|
44
|
Experimental study of the radiative decays K+-->mu(+)nue(+)e(-) and K+-->e(+)nue(+)e(-). PHYSICAL REVIEW LETTERS 2002; 89:061803. [PMID: 12190577 DOI: 10.1103/physrevlett.89.061803] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2002] [Indexed: 05/23/2023]
Abstract
Experiment 865 at the Brookhaven Alternating Gradient Synchrotron obtained 410 K+-->e(+)nue(+)e(-) and 2679 K+-->mu(+)nue(+)e(-) events including 10% and 19% background. The branching ratios were measured to be [2.48+/-0.14(stat)+/-0.14(syst)]x10(-8) (m(ee)>150 MeV) and (7.06+/-0.16+/-0.26)x10(-8) (m(ee)>145 MeV), respectively. Results for the decay form factors are presented.
Collapse
|
45
|
Positive and negative regulation of pathogen induced dendritic cell function by G-protein coupled receptors. Mol Immunol 2002; 38:891-3. [PMID: 12009566 DOI: 10.1016/s0161-5890(02)00015-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The induction of IL-12 from dendritic cells (DC) is a major initiating step in host resistance to intracellular pathogens. We have studied the regulation of this response using an in vivo model in which IL-12 production by splenic CD8alpha+ DC is followed after injection of a soluble extract (STAg) of the protozoan parasite Toxoplasma gondii. Our findings indicate that the potent IL-12 response observed is highly dependent on both the chemokine receptor CCR5 and G(i)-protein coupled signaling. In addition, we have examined the basis of the unresponsiveness of DC to secondary STAg injection which occurs following primary exposure to this parasite stimulus. Our results demonstrate that this refractory state correlates with the down-regulation of CCR5 expression on DC which, in turn, appears to depend on the induction of endogenous lipoxin A(4) (LXA(4)), a product of arachidonic acid metabolism. Since LXA(4) is known to also signal through a G-protein coupled receptor pathway, these findings taken together support a major role for G-protein signaling in the regulation of microbial-induced DC function.
Collapse
|
46
|
Lipoxin-mediated inhibition of IL-12 production by DCs: a mechanism for regulation of microbial immunity. Nat Immunol 2002; 3:76-82. [PMID: 11743584 DOI: 10.1038/ni745] [Citation(s) in RCA: 207] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Lipoxins are eicosanoid mediators that show potent inhibitory effects on the acute inflammatory process. We show here that the induction of lipoxin A(4) (LXA(4)) accompanied the in vivo suppression of interleukin 12 (IL-12) responsiveness of murine splenic dendritic cells (DCs) after microbial stimulation with an extract of Toxoplasma gondii. This paralysis of DC function could not be triggered in mice that were deficient in a key lipoxygenase involved in LXA(4) biosynthesis. In addition, DCs pre-treated with LXA(4) became refractory to microbial stimulation for IL-12 production in vitro and mice injected with a stable LXA(4) analog showed reduced splenic DC mobilization and IL-12 responses in vivo. Together, these findings indicate that the induction of lipoxins in response to microbial stimulation can provide a potent mechanism for regulating DC function during the innate response to pathogens.
Collapse
|
47
|
T-bet is rapidly induced by interferon-gamma in lymphoid and myeloid cells. Proc Natl Acad Sci U S A 2001; 98:15137-42. [PMID: 11752460 PMCID: PMC64996 DOI: 10.1073/pnas.261570598] [Citation(s) in RCA: 577] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/25/2001] [Indexed: 11/18/2022] Open
Abstract
Differentiation of naive CD4(+) T cells into IFN-gamma-producing T helper 1 (T(H)1) cells is pivotal for protective immune responses against intracellular pathogens. T-bet, a recently discovered member of the T-box transcription factor family, has been reported to play a critical role in this process, promoting IFN-gamma production. Although terminal T(H)1 differentiation occurs over days, we now show that challenge of mice with a prototypical T(H)1-inducing stimulus, Toxoplasma gondii soluble extract, rapidly induced IFN-gamma and T-bet; T-bet induction was substantially lower in IFN-gamma-deficient mice. Naive T cells expressed little T-bet, but this transcription factor was induced markedly by the combination of IFN-gamma and cognate antigen. Human myeloid antigen-presenting cells showed T-bet induction after IFN-gamma stimulation alone, and this induction was antagonized by IL-4 and granulocyte/macrophage colony-stimulating factor. Although T-bet was induced rapidly and directly by IFN-gamma, it was not induced by IFN-alpha, lipopolysaccharide, or IL-1, indicating that this action of IFN-gamma was specific. Moreover, T-bet induction was dependent on Stat1 but not Stat4. These data argue for a model in which IFN-gamma gene regulation involves an autocrine loop, whereby the cytokine regulates a transcription factor that promotes its own production. These findings substantially alter the current view of T-bet in IFN-gamma regulation and promotion of cell-mediated immune responses.
Collapse
|
48
|
Abstract
The Tec kinases Rlk and Itk are critical for full T cell receptor (TCR)-induced activation of phospholipase C-gamma and mitogen-activated protein kinase. We show here that the mutation of Rlk and Itk impaired activation of the transcription factors NFAT and AP-1 and production of both T helper type 1 (TH1) and TH2 cytokines. Consistent with these biochemical defects, Itk-/- mice did not generate effective TH2 responses when challenged with Schistosoma mansoni eggs. Paradoxically, the more severely impaired Rlk-/-Itk-/- mice were able to mount a TH2 response and produced TH2 cytokines in response to this challenge. In addition, Rlk-/-Itk-/- cells showed impaired TCR-induced repression of the TH2-inducing transcription factor GATA-3, suggesting a potential mechanism for TH2 development in these hyporesponsive cells. Thus, mutations that affect Tec kinases lead to complex alterations in CD4+ TH cell differentiation.
Collapse
|
49
|
New measurement of K(+)(e4) decay and the s-pave pi pi-scattering length a(0)(0). PHYSICAL REVIEW LETTERS 2001; 87:221801. [PMID: 11736394 DOI: 10.1103/physrevlett.87.221801] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2001] [Revised: 10/01/2001] [Indexed: 05/23/2023]
Abstract
A sample of 4 x 10(5) events from the decay K(+)-->pi(+)pi(-)e(+)nu(e) (K(e4)) has been collected in experiment E865 at the Brookhaven Alternating Gradient Synchrotron. The analysis of these data yields new measurements of the K(e4) branching ratio [(4.11+/-0.01+/-0.11) x 10(-5)], the s-wave pi pi scattering length [a(0)(0) = 0.216+/-0.013(stat)+/-0.004(syst)+/-0.005(theor)], and the form factors F, G, and H of the hadronic current and their dependence on the invariant pi pi mass.
Collapse
|
50
|
Mice infected with Schistosoma mansoni develop a novel non-T-lymphocyte suppressor population which inhibits virus-specific CTL induction via a soluble factor. Microbes Infect 2001; 3:1051-61. [PMID: 11709285 DOI: 10.1016/s1286-4579(01)01499-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We previously observed that Schistosoma mansoni-infected mice were deficient in their ability to mount a CTL response to unrelated viral antigens and to clear a vaccinia viral infection. Here, we explore the mechanism of that deficiency. Mixing experiments showed that splenocytes from S. mansoni-infected mice actively suppress stimulation in vitro of both viral-peptide specific CTL in spleen cells from virus-infected mice, and allospecific CTL. The mechanism of suppression involves at least in part a soluble factor, in that it can occur across a 0.4-microm membrane which prohibits direct cell contact. However, the inhibition is not alleviated by blocking with antibodies to IL-4, IL-10 or TGF-beta. Fractionation of the splenocyte population from S. mansoni-infected mice shows that the suppression is mediated by a non-B, non-T cell that expresses CD16 and Mac-1, but not FcepsilonR or NK1.1. This represents a novel suppressor population that is distinct from the FcepsilonRI(+) populations of non-B, non-T cells in the spleens of S. mansoni-infected mice that provide a major source of IL-4 in these animals. Similar cells in schistosome-infected humans could affect susceptibility to other infections or responsiveness to vaccines.
Collapse
|