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1.
Opt Lett ; 48(9): 2480-2483, 2023 May 01.
Article in English | MEDLINE | ID: mdl-37126304

ABSTRACT

The effect of realistic atmospheric conditions on mid-IR (λ = 3.9 µm) and long-wave-IR (λ = 10 µm) laser-induced avalanche breakdown for the remote detection of radioactive material is examined experimentally and with propagation simulations. Our short-range in-lab mid-IR laser experiments show a correlation between increasing turbulence level and a reduced number of breakdown sites associated with a reduction in the portion of the focal volume above the breakdown threshold. Simulations of propagation through turbulence are in excellent agreement with these measurements and provide code validation. We then simulate propagation through realistic atmospheric turbulence over a long range (0.1-1 km) in the long-wave-IR regime (λ = 10 µm). The avalanche threshold focal volume is found to be robust even in the presence of strong turbulence, only dropping by ∼50% over a propagation length of ∼0.6 km. We also experimentally assess the impact of aerosols on avalanche-based detection, finding that, while background counts increase, a useful signal is extractable even at aerosol concentrations 105 times greater than what is typically observed in atmospheric conditions. Our results show promise for the long-range detection of radioactive sources under realistic atmospheric conditions.

2.
Phys Rev Lett ; 129(20): 207201, 2022 Nov 11.
Article in English | MEDLINE | ID: mdl-36461990

ABSTRACT

Spinons are well known as the elementary excitations of one-dimensional antiferromagnetic chains, but means to realize spinons in higher dimensions is the subject of intense research. Here, we use resonant x-ray scattering to study the layered trimer iridate Ba_{4}Ir_{3}O_{10}, which shows no magnetic order down to 0.2 K. An emergent one-dimensional spinon continuum is observed that can be well described by XXZ spin-1/2 chains with a magnetic exchange of ∼55 meV and a small Ising-like anisotropy. With 2% isovalent Sr doping, magnetic order appears below T_{N}=130 K along with sharper excitations in (Ba_{1-x}Sr_{x})_{4}Ir_{3}O_{10}. Combining our data with exact diagonalization calculations, we find that the frustrated intratrimer interactions effectively reduce the system into decoupled spin chains, the subtle balance of which can be easily tipped by perturbations such as chemical doping. Our results put Ba_{4}Ir_{3}O_{10} between the one-dimensional chain and two-dimensional quantum spin liquid scenarios, illustrating a new way to suppress magnetic order and realize fractional spinons.

3.
Nat Mater ; 18(6): 563-567, 2019 06.
Article in English | MEDLINE | ID: mdl-30911120

ABSTRACT

Ruthenium compounds serve as a platform for fundamental concepts such as spin-triplet superconductivity1, Kitaev spin liquids2-5 and solid-state analogues of the Higgs mode in particle physics6,7. However, basic questions about the electronic structure of ruthenates remain unanswered, because several key parameters (including Hund's coupling, spin-orbit coupling and exchange interactions) are comparable in magnitude and their interplay is poorly understood, partly due to difficulties in synthesizing large single crystals for spectroscopic experiments. Here we introduce a resonant inelastic X-ray scattering (RIXS)8,9 technique capable of probing collective modes in microcrystals of 4d electron materials. We observe spin waves and spin-state transitions in the honeycomb antiferromagnet SrRu2O6 (ref. 10) and use the extracted exchange interactions and measured magnon gap to explain its high Néel temperature11-16. We expect that the RIXS method presented here will enable momentum-resolved spectroscopy of a large class of 4d transition-metal compounds.

4.
Nat Commun ; 15(1): 3496, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38664432

ABSTRACT

Magnetic van der Waals (vdW) materials have opened new frontiers for realizing novel many-body phenomena. Recently NiPS3 has received intense interest since it hosts an excitonic quasiparticle whose properties appear to be intimately linked to the magnetic state of the lattice. Despite extensive studies, the electronic character, mobility, and magnetic interactions of the exciton remain unresolved. Here we address these issues by measuring NiPS3 with ultra-high energy resolution resonant inelastic x-ray scattering (RIXS). We find that Hund's exchange interactions are primarily responsible for the energy of formation of the exciton. Measuring the dispersion of the Hund's exciton reveals that it propagates in a way that is analogous to a double-magnon. We trace this unique behavior to fundamental similarities between the NiPS3 exciton hopping and spin exchange processes, underlining the unique magnetic characteristics of this novel quasiparticle.

5.
Nat Commun ; 13(1): 913, 2022 Feb 17.
Article in English | MEDLINE | ID: mdl-35177583

ABSTRACT

Excitonic insulators are usually considered to form via the condensation of a soft charge mode of bound electron-hole pairs. This, however, presumes that the soft exciton is of spin-singlet character. Early theoretical considerations have also predicted a very distinct scenario, in which the condensation of magnetic excitons results in an antiferromagnetic excitonic insulator state. Here we report resonant inelastic x-ray scattering (RIXS) measurements of Sr3Ir2O7. By isolating the longitudinal component of the spectra, we identify a magnetic mode that is well-defined at the magnetic and structural Brillouin zone centers, but which merges with the electronic continuum in between these high symmetry points and which decays upon heating concurrent with a decrease in the material's resistivity. We show that a bilayer Hubbard model, in which electron-hole pairs are bound by exchange interactions, consistently explains all the electronic and magnetic properties of Sr3Ir2O7 indicating that this material is a realization of the long-predicted antiferromagnetic excitonic insulator phase.

6.
Phys Rev Lett ; 105(25): 255001, 2010 Dec 17.
Article in English | MEDLINE | ID: mdl-21231595

ABSTRACT

We show experimentally for the first time that two mutually attracting flux ropes may bounce back instead of merging together, leading to a variety of dynamics not expected from a two-dimensional model. Attraction forces due to flux rope currents compete with repulsion from field line bending of in-plane and out-of-plane magnetic fields and elastic plasma compression. Bouncing dynamics occurs if the line-bending force due to an out-of-plane field dominates. Otherwise, the ropes merge. Further reduction in the field line-bending force results in violently erratic magnetic states.

7.
Drug Alcohol Depend ; 207: 107799, 2020 02 01.
Article in English | MEDLINE | ID: mdl-31865058

ABSTRACT

INTRODUCTION: Opioid use disorder (OUD) is common among people in jail and is effectively treated with medications for OUD (MOUD). People with OUD may have an incomplete or inaccurate understanding of OUD and MOUD, and of how to access care. We evaluated an OUD treatment decision making (TDM) intervention to determine whether the intervention increased MOUD initiation post-release. METHODS: We conducted an observational retrospective cohort study of the TDM intervention on initiation of MOUD, individuals with records data indicating confirmed or suspected OUD incarcerated in four eligible jails were eligible to receive the intervention. Time-to-event analyses of the TDM intervention were conducted using Cox proportional hazard modeling with MOUD as the outcome. RESULTS: Cox proportional hazard modeling, with the intervention modeled as having a time-varying effect due to violation of the proportionality assumption, indicated that those receiving the TDM intervention (n = 568) were significantly more likely to initiate MOUD during the first month after release from jail (adjusted hazard ratio 6.27, 95 % C.I. 4.20-9.37), but not in subsequent months (AHR 1.33 95 % C.I. 0.94-1.89), adjusting for demographics, prior MOUD, or felony or gross misdemeanor arrest in the prior year compared to those not receiving the intervention (n = 3174). CONCLUSION: The TDM intervention was associated with a significantly higher relative hazard of starting MOUD, specifically during the first month after incarceration. However, a minority of all eligible people received any MOUD. Future research should examine ways to increase initiation on MOUD immediately after (or ideally during) incarceration.


Subject(s)
Behavior Therapy/methods , Opiate Substitution Treatment/statistics & numerical data , Opioid-Related Disorders/psychology , Patient Education as Topic/methods , Prisoners/psychology , Adolescent , Adult , Buprenorphine/therapeutic use , Decision Making , Female , Humans , Male , Middle Aged , Naltrexone/therapeutic use , Opiate Substitution Treatment/psychology , Opioid-Related Disorders/drug therapy , Patient Acceptance of Health Care/psychology , Patient Acceptance of Health Care/statistics & numerical data , Prisons , Proportional Hazards Models , Retrospective Studies , Young Adult
8.
Science ; 221(4613): 867-9, 1983 Aug 26.
Article in English | MEDLINE | ID: mdl-6308764

ABSTRACT

The mouse homolog (c-sis) of the transforming gene of the simian sarcoma virus was mapped to chromosome 15 by the Southern blot analysis of DNA's from hamster-mouse somatic cell hybrids. Alterations in c-sis expression may thus play a role in the various murine neoplastic diseases characterized by rearrangements or duplications of chromosome 15.


Subject(s)
Leukemia, Experimental/genetics , Oncogenes , Retroviridae/genetics , Sarcoma Virus, Woolly Monkey/genetics , Animals , Chromosome Aberrations/genetics , Chromosome Disorders , Chromosome Mapping , Mice , Nucleic Acid Hybridization
9.
Plant Dis ; 93(6): 673, 2009 Jun.
Article in English | MEDLINE | ID: mdl-30764432

ABSTRACT

Spinach (Spinacia oleracea) plants exhibiting severe stunting and leaves that showed interveinal yellowing, thickening, and deformation were found in an experimental trial adjacent to an artichoke field in Monterey County, CA in October of 2008. Percent incidence of symptomatic plants ranged from 20 to 39% in cvs. Bordeaux, Lazio, and Tigercat. Symptomatic plants were positive for Impatiens necrotic spot virus (INSV; family Bunyaviridae, genus Tospovirus) and were negative for Tomato spotted wilt virus, Cucumber mosaic virus, and Tobacco mosaic virus when tested with immunostrips (Agdia Inc., Elkhart, IN). The INSV-positive spinach was used for mechanical transmission to Nicotiana benthamiana, Chenopodium quinoa, and spinach. All inoculated plants were positive for INSV with immunostrips. To further confirm the presence of INSV, reverse transcription (RT)-PCR was conducted. Total RNA was extracted from the symptomatic spinach plants using a RNeasy Plant Kit (Qiagen Inc., Valencia, CA) and used as a template in RT-PCR using forward (5'-GGATGTAAGCCCTTCTTTGTAGTGG-3') and reverse (5'-CCTTCCAAGTCACCCTCTGATTG-3') primers specific to the INSV nucleoprotein (N) gene (GenBank Accession No. DQ425096). Amplicons of the expected size (approximately 364 bp) were obtained from both field-infected and mechanically inoculated spinach plants. Four amplicons were sequenced and compared with INSV N gene sequence in GenBank to confirm the identity of the products. Sequences obtained had 99% nucleotide identity with INSV sequences available under the GenBank Accession Nos. L20885, DQ523597, DQ523598, X66872, L20886, D00914, AB109100, and DQ425096. INSV can be one of the most serious viral pathogens of ornamental plants in North America and Europe. The host range of INSV is expanding and recent reports of INSV infection of vegetables include lettuce, peppers, peanut, and potato (1-4). To our knowledge, this is the first report of natural occurrence of INSV in spinach in California. Since INSV is vectored by thrips, its expanding natural host could make it an economically important problem in California and the United States. References: (1) S. T. Koike et al. Plant Dis. 92:1248, 2008. (2) R. A. Naidu et al. Online publication. doi:10.1094/PHP-2005-0727-01-HN, Plant Health Progress, 2005. (3) S. S Pappu et al. Plant Dis. 83:966, 1999. (4) K. L. Perry et al. Plant Dis. 89:340, 2005.

10.
J Neurol ; 255(6): 885-90, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18350354

ABSTRACT

BACKGROUND: Duplication of the pituitary stalk, morning glory disc anomaly and moya moya are rare malformations. The combination of these findings may be syndromic and may have an underlying genetic etiology. METHODS: Case report and review of the literature of neurological, ophthalmological, and neuroradiological findings including ophthalmic examination, MRI and MRA. CASE REPORT: A 2 year-old girl presented with reduced visual acuity and roving eye movements since birth. Ophthalmological workup revealed bilateral morning glory disc anomaly. MRI showed duplication of the pituitary stalk and caudal displacement of the floor of the third ventricle. MRA showed narrowing of the supraclinoid internal carotid arteries with focal narrowing of the proximal middle cerebral arteries consistent with early moya moya disease. CONCLUSIONS: Review of the literature of pituitary gland duplication and of the combination of morning glory disc anomaly and moya moya disease revealed only one previously reported case. However, the spectrum of this possibly syndromic presentation may be much broader and include various types of anterior midline defects and may have a common underlying genetic cause.


Subject(s)
Cerebral Arteries/pathology , Moyamoya Disease/complications , Nervous System Malformations/complications , Optic Disk/abnormalities , Pituitary Gland/abnormalities , Retina/abnormalities , Carotid Artery, Internal/pathology , Carotid Artery, Internal/physiopathology , Cerebral Arteries/physiopathology , Child, Preschool , Disease Progression , Female , Humans , Magnetic Resonance Angiography , Magnetic Resonance Imaging , Middle Cerebral Artery/pathology , Middle Cerebral Artery/physiopathology , Moyamoya Disease/physiopathology , Nervous System Malformations/physiopathology , Retinal Artery/abnormalities , Third Ventricle/abnormalities
11.
J Neonatal Perinatal Med ; 11(3): 257-263, 2018.
Article in English | MEDLINE | ID: mdl-30103354

ABSTRACT

BACKGROUND: The association between saturation of peripheral oxygenation (SpO2) fluctuation and severity of retinopathy of prematurity (ROP) is well elucidated in extremely low birth weight (ELBW) infants. Time spent in the Target range of SpO2 is also associated with the severity of ROP. METHODS: In a prospective observational study, the SpO2 of all ELBW infants admitted to our unit were monitored for the first four weeks of life, and averaged every minute for analysis. The percent time spent at SpO2 <90%, 90-95%, and >95% and weekly SpO2 fluctuations [as SpO2 coefficient of variation (CoV)] were calculated. RESULTS: During the study period 21 infants had moderate to severe ROP and 35 infants served as controls. Infants with moderate to severe ROP were smaller and younger than their controls [676±124 grams vs. 796±148 grams (p < 0.001); and 24.0±1.0 weeks vs. 25.0±1.7 weeks (p < 0.001) respectively]. There were no significant differences in time spent in the 90-95% range between groups (p = 0.66). However there was a significant increase in weekly SpO2 CoV in infants with moderate to severe ROP vs. controls (p = 0.007). CONCLUSION: In ELBW infants, there was an association between SpO2 fluctuation during the first four weeks of life and severity of ROP, although, no association was established with time spent in the target range of SpO2.


Subject(s)
Infant, Extremely Low Birth Weight/blood , Oximetry/methods , Oxygen Inhalation Therapy/adverse effects , Oxygen/blood , Retinopathy of Prematurity/physiopathology , Female , Humans , Infant , Infant, Newborn , Infant, Premature , Intensive Care Units, Neonatal , Male , Prospective Studies , Retinopathy of Prematurity/blood , Retinopathy of Prematurity/therapy , Risk Factors , Treatment Outcome
12.
Plant Dis ; 91(5): 633, 2007 May.
Article in English | MEDLINE | ID: mdl-30780718

ABSTRACT

Pelargonium zonate spot virus (PZSV) was first isolated from tomato in southern Italy in 1982 (1) and later was also reported from Spain (3) and France (2). Infected tomato plants showed stunting, malformation, yellow rings and line patterns on the leaves, and concentric chlorotic ringspots on the stems. In June of 2006, more than 100 tomato (Lycopersicon esculentum Mill.) plants exhibiting symptoms similar to PZSV were observed in seven acres of tomato fields in Yolo County, California. The causal agent was mechanically transmitted to several indicator species. Symptoms on infected plants included local lesions on Beta macrocarpa, Chenopodium amaranticolor, C. capitatum, C. quinoa, Cucumis melo, Cucurbita pepo, and Tetragonia expansa, and systemic infection on Capsicum annuum, Chenopodium murale, L. esculentum, Nicotiana benthamiana, N. clevelandii, N. glutinosa, N. tabacum, Physalis floridana, and P. wrightii. Two field-infected tomato plants and one each of the mechanically inoculated host plant were positive with double-antibody sandwich (DAS)-ELISA using a commercial PZSV IdentiKit (Neogen Europe Ltd., Ayr, Scotland, UK). Partially purified virions stained with 2% uranyl acetate contained spherical to ovate particles. The particle diameters ranged between 25 and 35 nm. Published sequences of PZSV (GenBank Accession Nos. NC_003649 for RNA1, NC_003650 for RNA2, and NC_003651 for RNA3) were used to design three sets of primer pairs specific for PZSV RNA1 (R1-F: 5' TGGCTGGCTTTTTCCGAACG 3' and R1-R: 5' CCTAATCTGTTGGTCCGAACTGTC 3'), RNA2 (R2-F: 5' GCGTGCGTATCATCAGAAATGG 3' and R2-R: 5' ATCGGGAGCAG AGAAACACCTTCC 3'), and RNA3 (R3-F: 5' CTCACCAACTGAAT GCTCTGGAC 3' and R3-R: 5' TGGATGCGTCTTTCCGAACC 3') for reverse transcription (RT)-PCR tests. Total nucleic acids were extracted from field-infected tomato plants and partially purified virions for RT-PCR. RT-PCR gave DNA amplicons of the expected sizes. The DNA amplicons were gel purified and sequenced. The sequenced amplicons had 92, 94, and 96% nt sequence identity to PZSV RNA1, RNA2, and RNA3, respectively. The symptomatology, serology, particle morphology, and nucleotide sequences confirm the presence of PZSV in a tomato field in California. To our knowledge, this is the first report of the occurrence of PZSV in the United States. References: (1) D. Gallitelli. Ann. Appl. Biol. 100:457, 1982. (2) K. Gebre-Selassie et al. Plant Dis. 86:1052, 2002. (3) M. Luis-Arteaga et al. Plant Dis. 84:807, 2000.

13.
Br J Ophthalmol ; 90(4): 429-31, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16547320

ABSTRACT

BACKGROUND/AIMS: Recent studies on the treatment of acute subretinal macular haemorrhage have shown that the volume of the clot and the time to evacuation have strong prognostic factors for visual outcome. A novel technique for surgical evacuation of these lesions involves direct injection of tissue plasminogen activator (t-PA) into the haematoma using pars plana vitrectomy. The aim of this study was to evaluate the clinical outcomes of this recently described procedure. METHODS: 17 consecutive patients with subretinal macular haemorrhages caused by age related macular degeneration were enrolled. Patient demographics, acuities, and fluorescein angiograms were obtained for all evaluations. All patients underwent complete three port pars plana vitrectomy to enable direct cannulation of the subretinal space and injection of 48 mug of t-PA, partial fluid-air exchange, 1 hour face up supine positioning postoperatively, followed by upright positioning overnight. RESULTS: 88% of patients within the study had stabilisation or improvement of visual acuity. Nine patients had total clearing of the macular haemorrhage and eight patients had subtotal clearing. Two patients had recurrence of the haemorrhage after the procedure and one patient underwent repair for retinal detachment. Occult lesions demonstrated similar outcomes to classic or predominately classic lesions. Nine patients required no therapy after the study to treat subfoveal neovascularisation. CONCLUSIONS: This study represents one of the largest case series to date showing that direct injection of subretinal t-PA with air-fluid exchange only and no intraoperative clot lysis period can have favourable results.


Subject(s)
Fibrinolytic Agents/administration & dosage , Retinal Hemorrhage/drug therapy , Tissue Plasminogen Activator/administration & dosage , Acute Disease , Aged , Aged, 80 and over , Choroidal Neovascularization/complications , Female , Fibrinolytic Agents/therapeutic use , Humans , Injections, Intralesional , Macular Degeneration/complications , Male , Middle Aged , Postoperative Care/methods , Posture , Retinal Hemorrhage/etiology , Retinal Hemorrhage/physiopathology , Tissue Plasminogen Activator/therapeutic use , Treatment Outcome , Visual Acuity/drug effects , Vitrectomy
14.
Plant Dis ; 89(5): 464-468, 2005 May.
Article in English | MEDLINE | ID: mdl-30795422

ABSTRACT

Rhizomania is an important virus disease of sugar beet and is caused by Beet necrotic yellow vein virus (BNYVV). During 2002-03, several sugar beet fields with cultivars partially resistant to BNYVV grown in the Imperial Valley of California were observed with severe rhizomania symptoms, suggesting that resistance conditioned by Rz1 had been compromised. Soil testing with sugar beet baiting plants followed by enzyme-linked immunosorbent assay (ELISA) was used to diagnose virus infection. Resistant varieties grown in BNYVV-infested soil from Salinas, CA, were ELISA-negative. In contrast, when grown in BNYVV-infested soil collected from the Imperial Valley, CA, all resistant varieties became infected and tested positive by ELISA. Based on host reaction, eight distinct BNYVV isolates have been identified from Imperial Valley soil (IV-BNYVV) by single local lesion isolation. Reverse transcription-polymerase chain reaction (RT-PCR) assays showed that the eight IV-BNYVV isolates did not contain RNA-5. Singlestrand conformation polymorphism banding patterns for the IV-BNYVV isolates were identical to A-type and different from P-type. Sequence alignments of PCR products from BNYVV RNA-1 near the 3' end of IV-BNYVV isolates revealed that both IV-BNYVV and Salinas BNYVV isolates were similar to A-type and different from B-type. Our results suggest that the resistancebreaking BNYVV isolates from Imperial Valley likely evolved from existing A-type isolates.

15.
Virus Res ; 79(1-2): 39-45, 2001 Nov 05.
Article in English | MEDLINE | ID: mdl-11551644

ABSTRACT

Endogenous retroviral sequences are present as an integral part of eukaryotic genomes. Although the majority of these sequences are defective, a few can produce infectious virus, either spontaneously upon long-term culture or by treatment with various chemical or other agents. Early, extensive studies of retrovirus induction were done in mouse cells; however, similar studies have not been done using state-of-the-art virus detection assays and with cells of other mammalian species. To investigate induction and detection of occult retroviruses in cells of different species, especially primate cells that are used in production of biologics, we have initially determined the optimum conditions for retrovirus induction in chemically treated K-BALB mouse cells using highly sensitive product-enhanced reverse transcriptase (PERT) assays as well as transmission electron microscopy (TEM). Retrovirus induction was detected at day 1 post-drug treatment under all test conditions but was optimum using 30 microg ml(-1) of 5-iododeoxyuridine (IdU) for 24 h. Additionally, the combination of IdU and 5-azacytidine specifically enhanced activation of type C particles. RT activity was detected by PERT assays in one microliter equivalent of test sample and retroviral particle production was seen by TEM analysis. The induction of infectious murine leukemia retroviruses was confirmed by infectivity assays and correlated with PERT activity. These results indicate that strategies for detection of occult viral agents should include optimization of induction conditions using multiple viral detection assays to evaluate virus activation.


Subject(s)
Endogenous Retroviruses/isolation & purification , 3T3 Cells , Animals , Antiviral Agents/pharmacology , Azacitidine/pharmacology , Endogenous Retroviruses/drug effects , Endogenous Retroviruses/growth & development , Idoxuridine/pharmacology , Mice , Mice, Inbred BALB C , Time Factors , Virus Activation
16.
J Clin Virol ; 11(1): 7-18, 1998 Jul 24.
Article in English | MEDLINE | ID: mdl-9784139

ABSTRACT

BACKGROUND: Reverse transcriptase (RT) activity has previously been reported in concentrated medium of primary chicken embryo cell cultures using the traditional RT assay. Recently, using the newly-developed and highly-sensitive product-enhanced reverse transcriptase (PERT) assay, RT activity has been detected in live, attenuated vaccines grown in chicken cell substrates. Furthermore, this activity has been associated with particles that contain RNA related to an ancient, endogenous avian retrovirus family designated as EAV-0. OBJECTIVE: To investigate whether the RT activity present in vaccines produced in specific pathogen-free chicken cell substrates is associated with an infectious retrovirus that can replicate in human cells. STUDY DESIGN: The kinetics of RT activity produced by 10-day-old chicken embryo fibroblast (CEF) cultures was determined by analyzing cell-free medium in a PCR-based RT (PBRT) assay. Material containing the peak PBRT activity was used as the inoculum to infect various human cell lines and peripheral blood mononuclear cells. Filtered supernatants from control and test cultures were analyzed for the presence of replication-competent retroviruses by the PBRT assay. The cells were monitored for other adventitious agents by routine observation for cytopathic effect (CPE) and by transmission electron microscopy (TEM) at culture termination. RESULTS: The PBRT activity did not increase above the background level in the human target cells through at least five cell passages, thus indicating the absence of a replicating retrovirus. No other adventitious agents were detected based upon TEM analysis and the absence of CPE. CONCLUSION: The RT activity produced by chicken primary cell cultures is not associated with a retrovirus that can replicate in human cells.


Subject(s)
RNA-Directed DNA Polymerase/metabolism , Retroviridae/physiology , Virus Replication , Animals , Cells, Cultured , Chick Embryo , Coculture Techniques , Culture Media , Cytopathogenic Effect, Viral , Humans , Kinetics , Microscopy, Electron , Retroviridae/enzymology , Reverse Transcriptase Polymerase Chain Reaction , Specific Pathogen-Free Organisms , Tumor Cells, Cultured
17.
Arch Ophthalmol ; 116(9): 1185-8, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9747676

ABSTRACT

BACKGROUND: Familial arteriolar tortuosity is an autosomal dominant disorder affecting the retinal arterioles. OBJECTIVES: To report a pedigree with this disorder and describe a systemic workup to determine whether this vascular abnormality is limited to the eye. RESULTS: A 58-year-old woman referred for retinal hemorrhages was found to have retinal arteriolar tortuosity of both eyes, especially in the macular area. Her 63-year-old brother had a history of retinal hemmorhages beginning at age 18 years and had similar fundoscopic examination findings. The proband had an extensive systemic workup, including magnetic resonance imaging, and cardiac and renal angiography, that failed to demonstrate any other sequelae of this inherited ocular syndrome. However, each member of the family expressing this phenotype did have hypertension. CONCLUSION: Inherited retinal arteriolar tortuosity is an autosomal dominant disorder limited to the eye, at least in this pedigree, within the sensitivity of the systemic workup we used.


Subject(s)
Eye Abnormalities/genetics , Retinal Artery/abnormalities , Retinal Hemorrhage/genetics , Adult , Aged , Aged, 80 and over , Eye Abnormalities/complications , Eye Abnormalities/pathology , Female , Fluorescein Angiography , Fundus Oculi , Humans , Male , Middle Aged , Pedigree , Retinal Artery/pathology , Retinal Hemorrhage/complications , Retinal Hemorrhage/pathology , Visual Acuity
18.
Ann Thorac Surg ; 54(3): 541-6, 1992 Sep.
Article in English | MEDLINE | ID: mdl-1510523

ABSTRACT

We examined components of the coagulation system in 30 neonates (age, 1 to 30 days) undergoing deep hypothermic cardiopulmonary bypass (CPB). A coagulation profile consisting of activated clotting time; prothrombin time; partial thromboplastin time; factors II, V, VII, VIII, IX, X, and I (fibrinogen); antithrombin III; platelet count; and heparin levels was evaluated before bypass, at three intervals during bypass (1 minute after initiation of bypass, stable hypothermic CPB, warm CPB), after weaning from CPB and administration of protamine, and 2 to 3 hours after skin closure. The initiation of CPB resulted in a 50% decrease in circulating coagulation factors and antithrombin III levels. Platelet counts were reduced by 70% with CPB initiation. Neither deep hypothermic temperatures nor prolonged exposure to extracorporeal surfaces had any additional effect on the coagulation profiles. This suggests that the coagulation system of a neonate undergoing CPB is profoundly and globally effected by hemodilution. We believe that treatment of post-CPB coagulopathy in neonates must address these global deficits.


Subject(s)
Blood Coagulation Disorders/etiology , Cardiopulmonary Bypass/adverse effects , Antithrombin III/analysis , Blood Coagulation Disorders/blood , Blood Coagulation Factors/analysis , Body Temperature , Fibrinogen/analysis , Heart Defects, Congenital/surgery , Humans , Infant, Newborn , Platelet Count , Protamines/administration & dosage
19.
J Magn Reson ; 151(1): 48-59, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11444936

ABSTRACT

A general strategy for the observation of low gamma half-integer quadrupolar nuclides in biological systems is presented. The methodology combines low-temperature (4-100 K) techniques with cross-polarization (CP) experiments while employing a so-called Carr-Purcell-Meiboom-Gill spin-echo sequence (CPMG). This combined approach is termed CP/QCPMG. Also discussed are data processing issues that are unique to the induced signals that result from the QCPMG pulse sequence. Central to this strategy is the development of a stable low-temperature (4 to 250 K) NMR double-resonance probe. The probe is robust enough to handle multiple contact experiments and long acquisition periods with 1H decoupling. This approach is illustrated with low-temperature solid-state 67Zn and 25Mg NMR CP/QCPMG experiments on model compounds. The conclusion reached is that the strategy affords sufficient sensitivity to examine Zn2+ and/or Mg2+ binding sites in metalloproteins.


Subject(s)
Magnetic Resonance Spectroscopy/methods , Fourier Analysis , Magnesium , Radioisotopes , Temperature , Zinc Radioisotopes
20.
Am J Ophthalmol ; 126(5): 723-5, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9822240

ABSTRACT

PURPOSE: To investigate the efficacy of ciliary body endophotocoagulation during pars plana vitrectomy in eyes of pediatric patients with medically uncontrolled glaucoma. METHOD: We compared preoperative and postoperative intraocular pressure and visual acuity in five eyes of five patients aged between 10 months and 14.5 years who had 180 degrees of ciliary body endophotocoagulation with pars plana vitrectomy. RESULTS: Preoperative intraocular pressure on medical therapy for glaucoma ranged from 30 to 55 mm Hg (median, 35 mm Hg). Postoperative follow-up ranged from 12 to 24 months, with a median of 16 months. Postoperative intraocular pressure on medical therapy ranged from 12 to 35 mm Hg (median, 25 mm Hg) at 6 weeks, from 12 to 33 mm Hg (median, 29 mm Hg) at 6 months, and from 12 to 29 mm Hg (median, 27 mm Hg) at 12 months. Twelve months after surgery, mean intraocular pressure reduction of 20 mm Hg was statistically significant (P = .020). CONCLUSION: Ciliary body endophotocoagulation during pars plana vitrectomy may be an effective treatment for pediatric patients with simultaneous uncontrolled glaucoma and vitreoretinal disorders.


Subject(s)
Ciliary Body/surgery , Glaucoma/surgery , Laser Coagulation , Retinal Diseases/surgery , Vitrectomy , Vitreous Body/surgery , Adolescent , Child , Child, Preschool , Eye Diseases/complications , Eye Diseases/surgery , Female , Glaucoma/complications , Humans , Infant , Intraocular Pressure , Male , Retinal Diseases/complications , Treatment Outcome , Visual Acuity
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