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1.
Transplant Proc ; 49(1): 206-209, 2017.
Article in English | MEDLINE | ID: mdl-28104138

ABSTRACT

BACKGROUND: With the introduction of the Kidney Allocation System in the United States in December 2014, transplant centers can list eligible B blood type recipients for A2 organ offers. There have been no prior reports of ABO incompatible A2 to B deceased donor kidney transplantation in human immunodeficiency virus-positive (HIV+) recipients to guide clinicians on enrolling or performing A2 to B transplantations in HIV+ candidates. We are the first to report a case of A2 to B deceased donor kidney transplantation in an HIV+ recipient with good intermediate-term results. METHODS AND RESULTS: We describe an HIV+ 39-year-old African American man with end-stage renal disease who underwent A2 to B blood type incompatible deceased donor kidney transplantation. Prior to transplantation, he had an undetectable HIV viral load. The patient was unsensitized, with his most recent anti-A titer data being 1:2 IgG and 1:32 IgG/IgM. Induction therapy of basiliximab and methylprednisolone was followed by a postoperative regimen of plasma exchange, intravenous immunoglobulin, and rituximab with maintenance on tacrolimus, mycophenolate mofetil, and prednisone. He had delayed graft function without rejection on allograft biopsy. Nadir serum creatinine was 2.0 mg/dL. He continued to have an undetectable viral load on the same antiretroviral therapy adjusted for renal function. CONCLUSIONS: To our knowledge, this is the first report of A2 to B deceased donor kidney transplantation in an HIV+ recipient with good intermediate-term results, suggesting that A2 donor kidneys may be considered for transplantation into HIV+ B-blood type wait list candidates.


Subject(s)
ABO Blood-Group System , Blood Group Incompatibility , HIV Infections/blood , Kidney Failure, Chronic/blood , Kidney Transplantation/methods , Adult , Delayed Graft Function/blood , Delayed Graft Function/virology , HIV Infections/surgery , HIV Infections/virology , Humans , Kidney Failure, Chronic/surgery , Kidney Failure, Chronic/virology , Male , Tissue Donors , Treatment Outcome
2.
J Assoc Res Otolaryngol ; 16(5): 631-40, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26055149

ABSTRACT

Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.


Subject(s)
Hearing Loss, Unilateral/physiopathology , Neural Conduction , Adult , Aged , Evoked Potentials, Auditory, Brain Stem/physiology , Female , Humans , Male , Middle Aged , Reaction Time
3.
Am J Transplant ; 15(4): 914-22, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25648884

ABSTRACT

Live donor kidney transplantation is the best treatment option for most patients with late-stage chronic kidney disease; however, the rate of living kidney donation has declined in the United States. A consensus conference was held June 5-6, 2014 to identify best practices and knowledge gaps pertaining to live donor kidney transplantation and living kidney donation. Transplant professionals, patients, and other key stakeholders discussed processes for educating transplant candidates and potential living donors about living kidney donation; efficiencies in the living donor evaluation process; disparities in living donation; and financial and systemic barriers to living donation. We summarize the consensus recommendations for best practices in these educational and clinical domains, future research priorities, and possible public policy initiatives to remove barriers to living kidney donation.


Subject(s)
Health Services Accessibility , Kidney Transplantation , Living Donors , Patient Education as Topic , Practice Guidelines as Topic , Humans
4.
Integr Environ Assess Manag ; 11(3): 348-54, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25655086

ABSTRACT

This brief communication reports on the main findings and recommendations from the 2014 Science Forum organized by CropLife America. The aim of the Forum was to gain a better understanding of the current status of population models and how they could be used in ecological risk assessments for threatened and endangered species potentially exposed to pesticides in the United States. The Forum panelists' recommendations are intended to assist the relevant government agencies with implementation of population modeling in future endangered species risk assessments for pesticides. The Forum included keynote presentations that provided an overview of current practices, highlighted the findings of a recent National Academy of Sciences report and its implications, reviewed the main categories of existing population models and the types of risk expressions that can be produced as model outputs, and provided examples of how population models are currently being used in different legislative contexts. The panel concluded that models developed for listed species assessments should provide quantitative risk estimates, incorporate realistic variability in environmental and demographic factors, integrate complex patterns of exposure and effects, and use baseline conditions that include present factors that have caused the species to be listed (e.g., habitat loss, invasive species) or have resulted in positive management action. Furthermore, the panel advocates for the formation of a multipartite advisory committee to provide best available knowledge and guidance related to model implementation and use, to address such needs as more systematic collection, digitization, and dissemination of data for listed species; consideration of the newest developments in good modeling practice; comprehensive review of existing population models and their applicability for listed species assessments; and development of case studies using a few well-tested models for particular species to demonstrate proof of concept. To advance our common goals, the panel recommends the following as important areas for further research and development: quantitative analysis of the causes of species listings to guide model development; systematic assessment of the relative role of toxicity versus other factors in driving pesticide risk; additional study of how interactions between density dependence and pesticides influence risk; and development of pragmatic approaches to assessing indirect effects of pesticides on listed species.


Subject(s)
Environmental Exposure/statistics & numerical data , Environmental Pollutants/analysis , Pesticides , Risk Assessment/methods , Agriculture/statistics & numerical data , Models, Theoretical , Population Growth , United States
5.
Am J Transplant ; 13(2): 450-7, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23205926

ABSTRACT

Most centers utilize phone or written surveys to screen candidates who self-refer to be living kidney donors. To increase efficiency and reduce resource utilization, we developed a web-based application to screen kidney donor candidates. The aim of this study was to evaluate the use of this web-based application. Method and time of referral were tabulated and descriptive statistics summarized demographic characteristics. Time series analyses evaluated use over time. Between January 1, 2011 and March 31, 2012, 1200 candidates self-referred to be living kidney donors at our center. Eight hundred one candidates (67%) completed the web-based survey and 399 (33%) completed a phone survey. Thirty-nine percent of donors accessed the application on nights and weekends. Postimplementation of the web-based application, there was a statistically significant increase (p < 0.001) in the number of self-referrals via the web-based application as opposed to telephone contact. Also, there was a significant increase (p = 0.025) in the total number of self-referrals post-implementation from 61 to 116 per month. An interactive web-based application is an effective strategy for the initial screening of donor candidates. The web-based application increased the ability to interface with donors, process them efficiently and ultimately increased donor self-referral at our center.


Subject(s)
Internet , Kidney Transplantation/methods , Tissue and Organ Procurement/methods , Adult , Body Mass Index , Cohort Studies , Female , Humans , Living Donors , Male , Middle Aged , Models, Statistical , Patient Education as Topic , Program Development , Referral and Consultation , Renal Insufficiency/therapy , Retrospective Studies , Software
7.
Acta Physiol (Oxf) ; 201(3): 365-72, 2011 Mar.
Article in English | MEDLINE | ID: mdl-20874802

ABSTRACT

AIM: Feeding protein after resistance exercise enhances the magnitude and duration of myofibrillar protein synthesis (MPS) over that induced by feeding alone. We hypothesized that the underlying mechanism for this would be a greater and prolonged phosphorylation of signalling involved in protein translation. METHODS: Seven healthy young males performed unilateral resistance exercise followed immediately by the ingestion of 25 g of whey protein to maximally stimulate MPS in a rested and exercised leg. RESULTS: Phosphorylation of p70 ribosomal protein S6 kinase (p70S6K) was elevated (P<0.05) above fasted at 1 h at rest whereas it was elevated at 1, 3 and 5 h after exercise with protein ingestion and displayed a similar post-exercise time course to that shown by MPS. Extracellular regulated kinase1/2 (ERK1/2) and p90 ribosomal S6 kinase (p90RSK) phosphorylation were unaltered after protein ingestion at rest but were elevated (P < 0.05) above fasted early in recovery (1 h) and were greater for the exercised-fed leg than feeding alone (main effect; P < 0.01). Eukaryotic elongation factor 2 (eEF2) phosphorylation was also less (main effect; P<0.05) in the exercised-fed leg than in the rested leg suggesting greater activity after exercise. Eukaryotic initiation 4E binding protein-1 (4EBP-1) phosphorylation was increased (P<0.05) above fasted to the same extent in both conditions. CONCLUSION: Our data suggest that resistance exercise followed by protein feeding stimulates MPS over that induced by feeding alone in part by enhancing the phosphorylation of select proteins within the mammalian target of rapamycin (p70S6K, eEF2) and by activating proteins within the mitogen-activated protein kinase (ERK1/2, p90RSK) signalling.


Subject(s)
Dietary Proteins/metabolism , Exercise/physiology , Mitogen-Activated Protein Kinases/metabolism , Muscle, Skeletal/physiology , Resistance Training/methods , Signal Transduction/physiology , TOR Serine-Threonine Kinases/metabolism , Adult , Humans , Male
8.
Hear Res ; 229(1-2): 148-57, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17275232

ABSTRACT

Our knowledge of the function of the auditory nervous system is based upon a wealth of data obtained, for the most part, in anaesthetised animals. More recently, it has been generally acknowledged that factors such as attention profoundly modulate the activity of sensory systems and this can take place at many levels of processing. Imaging studies, in particular, have revealed the greater activation of auditory areas and areas outside of sensory processing areas when attending to a stimulus. We present here a brief review of the consequences of such non-passive listening and go on to describe some of the experiments we are conducting to investigate them. In imaging studies, using fMRI, we can demonstrate the activation of attention networks that are non-specific to the sensory modality as well as greater and different activation of the areas of the supra-temporal plane that includes primary and secondary auditory areas. The profuse descending connections of the auditory system seem likely to be part of the mechanisms subserving attention to sound. These are generally thought to be largely inactivated by anaesthesia. However, we have been able to demonstrate that even in an anaesthetised preparation, removing the descending control from the cortex leads to quite profound changes in the temporal patterns of activation by sounds in thalamus and inferior colliculus. Some of these effects seem to be specific to the ear of stimulation and affect interaural processing. To bridge these observations we are developing an awake behaving preparation involving freely moving animals in which it will be possible to investigate the effects of consciousness (by contrasting awake and anaesthetized), passive and active listening.


Subject(s)
Auditory Perception/physiology , Acoustic Stimulation , Animals , Attention/physiology , Auditory Cortex/anatomy & histology , Auditory Cortex/physiology , Auditory Pathways/physiology , Humans , Magnetic Resonance Imaging , Models, Animal , Models, Neurological , Models, Psychological , Visual Cortex/anatomy & histology , Visual Cortex/physiology , Visual Perception/physiology
9.
Neuroimage ; 30(4): 1112-20, 2006 May 01.
Article in English | MEDLINE | ID: mdl-16473021

ABSTRACT

The medial geniculate body (MGB) of the thalamus is a key component of the auditory system. It is involved in relaying and transforming auditory information to the cortex and in top-down modulation of processing in the midbrain, brainstem, and ear. Functional imaging investigations of this region in humans, however, have been limited by the difficulty of distinguishing MGB from other thalamic nuclei. Here, we introduce two methods for reliably delineating MGB anatomically in individuals based on conventional and diffusion MRI data. The first uses high-resolution proton density weighted scanning optimized for subcortical grey-white contrast. The second uses diffusion-weighted imaging and probabilistic tractography to automatically segment the medial and lateral geniculate nuclei from surrounding structures based on their distinctive patterns of connectivity to the rest of the brain. Both methods produce highly replicable results that are consistent with published atlases. Importantly, both methods rely on commonly available imaging sequences and standard hardware, a significant advantage over previously described approaches. In addition to providing useful approaches for identifying the MGB and LGN in vivo, our study offers further validation of diffusion tractography for the parcellation of grey matter regions on the basis of their connectivity patterns.


Subject(s)
Auditory Pathways/anatomy & histology , Diffusion Magnetic Resonance Imaging , Geniculate Bodies/anatomy & histology , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Thalamic Nuclei/anatomy & histology , Adult , Auditory Cortex/anatomy & histology , Auditory Perception/physiology , Brain Mapping , Brain Stem/anatomy & histology , Dominance, Cerebral/physiology , Female , Humans , Male , Reference Values
10.
Ecotoxicology ; 14(8): 895-923, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16328714

ABSTRACT

Long term exposure of skylarks to a fictitious insecticide and of wood mice to a fictitious fungicide were modelled probabilistically in a Monte Carlo simulation. Within the same simulation the consequences of exposure to pesticides on reproductive success were modelled using the toxicity-exposure-linking rules developed by R.S. Bennet et al. (2005) and the interspecies extrapolation factors suggested by R. Luttik et al. (2005). We built models to reflect a range of scenarios and as a result were able to show how exposure to pesticide might alter the number of individuals engaged in any given phase of the breeding cycle at any given time and predict the numbers of new adults at the season's end.


Subject(s)
Environmental Pollutants/toxicity , Models, Statistical , Pesticides/toxicity , Reproduction/drug effects , Animals , Birds , Environmental Exposure , Mice , Monte Carlo Method , Risk Assessment , Time , Triticum
11.
Ecotoxicology ; 14(8): 877-93, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16328715

ABSTRACT

In the European Union, first-tier assessment of the long-term risk to birds and mammals from pesticides is based on calculation of a deterministic long-term toxicity/exposure ratio (TER(lt)). The ratio is developed from generic herbivores and insectivores and applied to all species. This paper describes two case studies that implement proposed improvements to the way long-term risk is assessed. These refined methods require calculation of a TER for each of five identified phases of reproduction (phase-specific TERs) and use of adjusted No Observed Effect Levels (NOELs) to incorporate variation in species sensitivity to pesticides. They also involve progressive refinement of the exposure estimate so that it applies to particular species, rather than generic indicators, and relates spraying date to onset of reproduction. The effect of using these new methods on the assessment of risk is described. Each refinement did not necessarily alter the calculated TER value in a way that was either predictable or consistent across both case studies. However, use of adjusted NOELs always reduced TERs, and relating spraying date to onset of reproduction increased most phase-specific TERs. The case studies suggested that the current first-tier TER(lt )assessment may underestimate risk in some circumstances and that phase-specific assessments can help identify appropriate risk-reduction measures. The way in which deterministic phase-specific assessments can currently be implemented to enhance first-tier assessment is outlined.


Subject(s)
Environmental Exposure , Environmental Pollutants/toxicity , Pesticides/toxicity , Reproduction/drug effects , Animals , Birds , Crops, Agricultural , Edible Grain , Mammals , No-Observed-Adverse-Effect Level , Poaceae , Risk Assessment/methods , Time
12.
Int J Obes (Lond) ; 29(4): 443-6, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15700046

ABSTRACT

Following the withdrawal of ephedrine from the dietary supplement marketplace sales of products containing Citrus aurantium (CA) (bitter orange) for weight loss are believed to have increased dramatically. CA contains a number of constituents speculated to lead to weight loss, of which the most frequently cited constituent is synephrine. Concerns have been raised about the safety of products containing synephrine. To develop an adequate basis for clinical and public health recommendations, it is necessary to understand the nature of the synephrine alkaloids in CA. There are six possible isomers of synephrine (para, meta, ortho; and for each a d or l form). Some authors have stated that CA contains only p-synephrine, whereas other authors have stated that CA contains m-synephrine. This is an important distinction because the two molecules have different pharmacologic properties, which may differentially affect safety and efficacy. We are unable to identify published data that explicitly show whether CA contains p-synephrine, m-synephrine, or both. In this brief report, we show that at least one product purportedly containing synephrine alkaloids from CA contains both p-synephrine and m-synephrine. We believe this justifies further investigation into which synephrine alkaloids are present in CA and products purportedly containing synephrine alkaloids from CA and the relative quantities of each of the different isomers.


Subject(s)
Alkaloids/analysis , Citrus/chemistry , Dietary Supplements/analysis , Nonprescription Drugs/chemistry , Synephrine/analysis , Chromatography, Liquid , Humans , Mass Spectrometry , Protein Isoforms/analysis
13.
Food Addit Contam ; 19(8): 770-8, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12227941

ABSTRACT

Dioxins and dioxin-like PCBs are given toxic equivalency factors (TEFs) in order to calculate the combined toxic equivalence (TEQ) of these contaminants in a sample of food. This study calculates the probability of an average consumer exceeding the recommended tolerable daily intake of 1-4 pg WHO-TEQ kg(-1) bw day(-1) as the amount of salmon in the diet is increased. Probabilistic risk analysis is used to account for the known uncertainties in this calculation. When the TEF uncertainty was excluded with no salmon consumption, the background dietary intake ranged from 1.36 to 1.78 pg TEQ kg(-1) bw day(-1). A weekly consumption of three standard salmon portions resulted in a 36% chance of exceeding the upper limit of the TDI. Inclusion of the TEF uncertainty increased the background dietary intake range from 2.1 to 4.4 pg TEQ kg(-1) bw day(-1), and the weekly consumption of one salmon portion resulted in a 79% chance of the average consumer exceeding the upper TDI. The most important factors contributing to the uncertainty in these results were, in order of magnitude, the TEF for PCB 126 and the sampling uncertainty (sample size) followed by the measurement uncertainty of PCB 126. We recommend that it is more important to increase sample size and produce more precise estimates in the TEF than to improve analytical accuracy.


Subject(s)
Dioxins/analysis , Food Contamination/analysis , Polychlorinated Dibenzodioxins/analogs & derivatives , Salmon , Animals , Benzofurans/analysis , Diet , Humans , Maximum Allowable Concentration , Meat , Monte Carlo Method , Polychlorinated Biphenyls/analysis , Polychlorinated Dibenzodioxins/analysis , Risk Assessment/methods
14.
Hear Res ; 161(1-2): 113-22, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11744287

ABSTRACT

Ototoxicity following combined exposure to noise and carbon monoxide (CO) is known to result in more severe permanent threshold shifts than exposure to noise alone. We have previously demonstrated that such potentiation of noise-induced auditory impairment by CO can be prevented by the administration of a nitrone spin-trapping agent. Although such protection implicates injury via free radical pathways, drug-induced protection does not provide direct evidence for the presence of free radicals in the cochlea. The objective of this study was to demonstrate the actual presence of nitrone spin adducts in the cochlea following simultaneous exposure to noise and CO. Using electrophysiological end-points, the protective effects of the nitrone spin-trapping agent alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN) were assessed following combined exposure of adult male Long Evans hooded rats to noise and CO. In addition, an ex-vivo evaluation of POBN spin adducts was done by electron paramagnetic resonance spectroscopy (EPR). The noise used was octave band noise with center frequency 13.6 kHz at 100 dB(Lin) for a duration of 2 h. The level of CO used was 1200 ppm. Electrophysiological results demonstrate that POBN protects against combined exposure to noise plus CO. The EPR study demonstrates POBN spin adducts in the cochleae of animals exposed to noise plus CO. Therefore, this study provides evidence to the hypothesis that ototoxicity due to noise plus CO exposure is mediated via free radicals.


Subject(s)
Carbon Monoxide/pharmacology , Cochlea/drug effects , Cochlea/metabolism , Free Radicals/metabolism , Noise , Animals , Electron Spin Resonance Spectroscopy , Electrophysiology , Male , Nitrogen Oxides/pharmacology , Pyridines , Rats , Rats, Long-Evans , Spin Labels
15.
Audiol Neurootol ; 6(4): 182-6, 2001.
Article in English | MEDLINE | ID: mdl-11694724

ABSTRACT

The location of a sound source is derived by the auditory system from spatial cues present in the signals at the two ears. These cues include interaural timing and level differences, as well as monaural spectral cues generated by the external ear. The values of these cues vary with individual differences in the shape and dimensions of the head and external ears. We have examined the neurophysiological consequences of these intersubject variations by recording the responses of neurons in ferret primary auditory cortex to virtual sound sources mimicking the animal's own ears or those of other ferrets. For most neurons, the structure of the spatial response fields changed significantly when acoustic cues measured from another animal were presented. This is consistent with the finding that humans localize less accurately when listening to virtual sounds from other subjects. To examine the role of experience in shaping the ability to localize sound, we have studied the behavioural consequences of altering binaural cues by chronically plugging one ear. Ferrets raised and tested with one ear plugged learned to localize as accurately as control animals, which is consistent with previous findings that the representation of auditory space in the midbrain can accommodate abnormal sensory cues during development. Adaptive changes in behaviour were also observed in adults, particularly if they were provided with regular practice in the localization task. Together, these findings suggest that the neural circuits responsible for sound localization can be recalibrated throughout life.


Subject(s)
Auditory Cortex/physiology , Neuronal Plasticity/physiology , Space Perception/physiology , Animals , Humans , Sound Localization/physiology , Superior Colliculi/physiology
16.
Audiol Neurootol ; 6(4): 216-20, 2001.
Article in English | MEDLINE | ID: mdl-11694731

ABSTRACT

Conductive hearing loss produced by middle ear disease (MED) is very prevalent in the first 5 years of childhood. Both MED in children and prolonged ear plugging in animals lead to a binaural hearing impairment that persists beyond the duration of the peripheral impairment. However, after cessation of the MED, or removal of the ear plug, binaural hearing gradually improves. We suggest here that this improvement is a passive form of auditory learning. We also show that active auditory learning, through repetition of discrimination tasks, can accelerate performance increments, both after hearing loss and in unimpaired individuals. A more detailed understanding of auditory learning holds out the prospect of improving rehabilitation strategies for the language- and hearing-impaired.


Subject(s)
Auditory Cortex/physiopathology , Hearing Loss, Central/physiopathology , Hearing Loss, Central/rehabilitation , Hearing Loss, Conductive/physiopathology , Hearing Loss, Conductive/rehabilitation , Auditory Threshold/physiology , Child , Hearing Loss, Bilateral/etiology , Hearing Loss, Bilateral/physiopathology , Hearing Loss, Bilateral/rehabilitation , Hearing Loss, Central/etiology , Hearing Loss, Conductive/etiology , Humans , Otitis Media/complications , Perceptual Masking/physiology , Speech Perception/physiology
18.
Pancreas ; 23(3): 316-22, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11590329

ABSTRACT

INTRODUCTION: Proinflammatory cytokines may play a pivotal role in the pathogenesis of insulin-dependent diabetes mellitus (IDDM). In vitro, the formation of nitric oxide (NO) catalyzed by inducible NO synthase (iNOS) has been shown to be involved in the cytotoxic effects of cytokines on pancreatic beta cells. Cytokines have also been shown to cause the expression of inducible cyclooxygenase (COX-2) in isolated islets. AIMS: To describe a novel in vivo model that allows investigation of the effects of direct cytokine administration to the pancreas. METHODOLOGY AND RESULTS: By using this method, we demonstrate that administration of interleukin-1beta and interferon-gamma to rat pancreas results in the generation of NO in the treated pancreata as detected by NO trapping and electron paramagnetic resonance spectroscopy. Beta cells were identified as the source of the formed NO. Reverse transcription and polymerase chain reaction analyses showed that administration of cytokines to the pancreas leads to the expression of iNOS and COX-2 mRNA in the pancreas tissue as well as the islets isolated from such tissues. The compound phenyl N-tert-butylnitrone, which protects mice against streptozotocin-induced IDDM, inhibits NO formation and downregulates both iNOS and COX-2 mRNA levels.


Subject(s)
Interferon-gamma/administration & dosage , Interleukin-1/administration & dosage , Isoenzymes/genetics , Nitric Oxide Synthase/genetics , Nitric Oxide/biosynthesis , Pancreas/metabolism , Prostaglandin-Endoperoxide Synthases/genetics , Alloxan/pharmacology , Animals , Cyclic N-Oxides , Cyclooxygenase 2 , Gene Expression , Islets of Langerhans/metabolism , Male , Nitric Oxide Synthase Type II , Nitrogen Oxides/pharmacology , RNA, Messenger/analysis , Rats , Rats, Wistar , Reverse Transcriptase Polymerase Chain Reaction
19.
Curr Biol ; 11(19): R782-4, 2001 Oct 02.
Article in English | MEDLINE | ID: mdl-11591337

ABSTRACT

Lesion studies have suggested that the auditory cortex may not be involved in many aspects of hearing. A recent report casts doubt on this long-held view by showing that reversible inactivation of the auditory cortex leads to a transient impairment in tone detection and frequency discrimination.


Subject(s)
Auditory Cortex/physiology , Hearing/physiology , Animals , Humans
20.
J Am Chem Soc ; 123(36): 8738-49, 2001 Sep 12.
Article in English | MEDLINE | ID: mdl-11535078

ABSTRACT

Synthetic routes to zinc beta-diiminate complexes are reported. The synthesis of 11 beta-diimine [(BDI)-H] ligands, with varying N-aryl substituents and bridging structures, is described. These ligands are converted to (BDI)ZnX complexes (X = OAc, Et, N(SiMe3)2, Br, Cl, OH, OMe, O(i)Pr). X-ray structural data revealed that all zinc complexes examined exist as micro-X-bridged dimers in the solid state, with the exception of the zinc ethyl and amido complexes which were monomeric. Complexes of the form (BDI)ZnOR (R = alkyl, acyl) and (BDI)ZnN(SiMe3)2 are highly active catalysts for the alternating copolymerization of epoxides and CO2. Copolymerizations of cyclohexene oxide (CHO) and CO2 with (BDI-1)ZnX [(BDI-1) = 2-((2,6-diisopropylphenyl)amido)-4-((2,6-diisopropylphenyl)imino)-2-pentene)] and (BDI-2)ZnX [(BDI-2) = 2-((2,6-diethylphenyl)amido)-4-((2,6-diethylphenyl)imino)-2-pentene)], where X = OAc, Et, N(SiMe3)2, Br, Cl, OH, OMe, O(i)Pr, were attempted at 50 degrees C and 100 psi CO2. Complexes with X = OAc, N(SiMe3)2, OMe, O(i)Pr all produced polycarbonate by the alternated insertion of CHO and CO2 with similar catalytic activities, comparable molecular weights, and narrow molecular weight distributions (MWD approximately 1.1), indicating the copolymerizations are living. Furthermore, ligand effects were shown to dramatically influence the polymerization activity as minor steric changes accelerated or terminated the polymerization activity.

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