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Iris
Terms modified by Iris Selected AbstractsThe development and validation of the Indigenous Risk Impact Screen (IRIS): a 13-item screening instrument for alcohol and drug and mental health riskDRUG AND ALCOHOL REVIEW, Issue 2 2007CARLA M. SCHLESINGER Abstract The study aimed to assess the psychometric properties of the Indigenous Risk Impact Screen (IRIS) as a screening instrument for determining (i) the presence of alcohol and drug and mental health risk in Indigenous adult Australians and (ii) the cut-off scores that discriminate most effectively between the presence and absence of risk. A cross-sectional survey was used in clinical and non-clinical Indigenous and non-Indigenous services across Queensland Australia. A total of 175 Aboriginal and Torres Strait Islander people from urban, rural, regional and remote locations in Queensland took part in the study. Measures included the Indigenous Risk Impact Screen (IRIS), the Severity of Dependence Scale (SDS), the Alcohol Use Disorders Identification Test (AUDIT) and the Leeds Dependence Questionnaire (LDQ). Additional Mental Health measures included the Depression Anxiety and Stress Scale (DASS-21) and the Self-Report Questionnaire (SRQ). Principle axis factoring analysis of the IRIS revealed two factors corresponding with (i) alcohol and drug and (ii) mental health. The IRIS alcohol and drug and mental health subscales demonstrated good convergent validity with other well-established screening instruments and both subscales showed high internal consistency. A receiver operating characteristics (ROC) curve analysis was used to generate cut-offs for the two subscales and t-tests validated the utility of these cut-offs for determining risky levels of drinking. The study validated statistically the utility of the IRIS as a screen for alcohol and drug and mental health risk. The instrument is therefore recommended as a brief screening instrument for Aboriginal and Torres Strait Islander people. [source] A Comparison of Neural Network, Statistical Methods, and Variable Choice for Life Insurers' Financial Distress PredictionJOURNAL OF RISK AND INSURANCE, Issue 3 2006Patrick L. Brockett This study examines the effect of the statistical/mathematical model selected and the variable set considered on the ability to identify financially troubled life insurers. Models considered are two artificial neural network methods (back-propagation and learning vector quantization (LVQ)) and two more standard statistical methods (multiple discriminant analysis and logistic regression analysis). The variable sets considered are the insurance regulatory information system (IRIS) variables, the financial analysis solvency tracking (FAST) variables, and Texas early warning information system (EWIS) variables, and a data set consisting of twenty-two variables selected by us in conjunction with the research staff at TDI and a review of the insolvency prediction literature. The results show that the back-propagation (BP) and LVQ outperform the traditional statistical approaches for all four variable sets with a consistent superiority across the two different evaluation criteria (total misclassification cost and resubstitution risk criteria), and that the twenty-two variables and the Texas EWIS variable sets are more efficient than the IRIS and the FAST variable sets for identification of financially troubled life insurers in most comparisons. [source] Immune reconstitution inflammatory syndrome (IRIS) as a cause for inhibitor development in hemophiliaJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 1 2004S. Werwitzke No abstract is available for this article. [source] Chronic lung disease in human immunodeficiency virus (HIV) infected children,PEDIATRIC PULMONOLOGY, Issue 1 2008Heather J. Zar Abstract The development of chronic lung disease is common in HIV-infected children. The spectrum of chronic HIV-associated lung disease includes lymphocytic interstitial pneumonia (LIP), chronic infections, immune reconstitution inflammatory syndrome (IRIS), bronchiectasis, malignancies, and interstitial pneumonitis. Chronic lung disease may result from recurrent or persistent pneumonia due to bacterial, mycobacterial, viral, fungal or mixed infections. In high tuberculosis (TB) prevalence areas, M. tuberculosis is an important cause of chronic respiratory illness. With increasing availability of highly active antiretroviral therapy (HAART) for children in developing countries, a rise in the incidence of IRIS due to mycobacterial or other infections is being reported. Diagnosis of chronic lung disease is based on chronic symptoms and persistent chest X-ray changes but definitive diagnosis can be difficult as clinical and radiological findings may be non-specific. Distinguishing LIP from miliary TB remains a difficult challenge in HIV-infected children living in high TB prevalence areas. Treatment includes therapy for specific infections, pulmonary clearance techniques, corticosteroids for children with LIP who are hypoxic or who have airway compression from tuberculous nodes and HAART. Children who are taking TB therapy and HAART need adjustments in their drug regimes to minimize drug interactions and ensure efficacy. Preventative strategies include immunization, chemoprophylaxis, and micronutrient supplementation. Early use of HAART may prevent the development of chronic lung disease. Pediatr Pulmonol. 2008; 43:1,10. © 2007 Wiley-Liss, Inc. [source] Discrepancies between isotope ratio infrared spectroscopy and isotope ratio mass spectrometry for the stable isotope analysis of plant and soil watersRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 14 2010Adam G. West The use of isotope ratio infrared spectroscopy (IRIS) for the stable hydrogen and oxygen isotope analysis of water is increasing. While IRIS has many advantages over traditional isotope ratio mass spectrometry (IRMS), it may also be prone to errors that do not impact upon IRMS analyses. Of particular concern is the potential for contaminants in the water sample to interfere with the spectroscopy, thus leading to erroneous stable isotope data. Water extracted from plant and soil samples may often contain organic contaminants. The extent to which contaminants may interfere with IRIS and thus impact upon data quality is presently unknown. We tested the performance of IRIS relative to IRMS for water extracted from 11 plant species and one organic soil horizon. IRIS deviated considerably from IRMS for over half of the samples tested, with deviations as large as 46, (,2H) and 15.4, (,18O) being measured. This effect was reduced somewhat by using activated charcoal to remove organics from the water; however, deviations as large as 35, (,2H) and 11.8, (,18O) were still measured for these cleaned samples. Interestingly, the use of activated charcoal to clean water samples had less effect than previously thought for IRMS analyses. Our data show that extreme caution is required when using IRIS to analyse water samples that may contain organic contaminants. We suggest that the development of new cleaning techniques for removing organic contaminants together with instrument-based software to flag potentially problematic samples are necessary to ensure accurate plant and soil water analyses using IRIS. Copyright © 2010 John Wiley & Sons, Ltd. [source] Pulmonary complications of immune reconstitution inflammatory syndromes in HIV-infected patientsRESPIROLOGY, Issue 4 2009Kristina CROTHERS ABSTRACT Immune reconstitution inflammatory syndrome (IRIS) describes a paradoxical worsening of clinical status related to recovery of the immune system, as can occur after the initiation of highly active antiretroviral therapy (HAART) in HIV-infected patients. Most commonly, IRIS results from opportunistic infections that can unmask or develop paradoxical worsening following HAART. Cancers, autoimmune conditions and sarcoidosis have also been associated with IRIS. Pulmonary complications may be frequently encountered. This article reviews the types and clinical presentation of IRIS, with a focus on the pulmonary manifestations. Management and outcome of IRIS are considered. [source] EXILE FROM PERFECTION IN IRIS MURDOCH'S PHILOSOPHICAL TEXTSTHE HEYTHROP JOURNAL, Issue 1 2010TONY MILLIGAN Iris Murdoch's philosophical texts set out the egocentric dangers of guilt but still endorse an account of original sin. This might seem like an unstable combination as these two are in tension, but I argue that Murdoch manages to use this tension in a productive manner. The human condition is treated as one of fallenness, in the sense of an exile from perfection. We are aware of moral failure and also aware of the standard by which we fail. Guilt is reined in, however, by the fact that such failure is a matter of commonplace flawed moral vision and not an Augustinian perversity of the will. This reining in of guilt is still accompanied by a recognition of our unbridgeable remoteness from perfection. [source] FRAMING THE HUMAN CONDITION: THE EXISTENTIAL DILEMMA IN IRIS MURDOCH'S THE BELL AND MURIEL SPARK'S ROBINSONTHE HEYTHROP JOURNAL, Issue 5 2007MICHAEL GIFFIN One of the features of modernist and postmodernist novels is the way they interrogate classical metaphysics, in the spirit of what Habermas calls post-metaphysical thinking, otherwise known as the post-Enlightenment critique of the Enlightenment. As a literary prism, post-metaphysical thinking is not anti-metaphysical: it conducts its interrogation and still accommodates both secular and religious frames. Iris Murdoch and Muriel Spark are often compared but they interrogate classical metaphysics from different perspectives and for different purposes. In the nineteen-fifties, Murdoch was an aspiring philosophical author who treated classical metaphysics as a canon of influential myth, while Spark was an aspiring theological author who had recently converted to Catholicism. Through a reading of The Bell and Robinson, both published in the same year, this article describes how the young Murdoch and Spark do what emerging literary authors of the nineteen-fifties were expected to do: frame the human condition and reflect on its existential dilemma. With their different perspectives they both write within the same paradigm, or theory of mind; against symbolic backgrounds, and among significant dialogues, they make use of similar tropes. But Murdoch and Spark arrive at opposite positions on the relationship between imagination and reality, between logos and mythos, and ultimately on the nature of freedom and contingency. [source] Cellulitis Revealing a Cryptococcosis-Related Immune Reconstitution Inflammatory Syndrome in a Renal Allograft RecipientAMERICAN JOURNAL OF TRANSPLANTATION, Issue 12 2007F. Lanternier Immune reconstitution inflammatory syndrome (IRIS) has rarely been described in the course of disseminated cryptococcosis in solid organ transplant recipients. We report here the case of a renal transplant recipient who developed severe cellulitis in the context of Cryptococcus neoformans -associated IRIS while undergoing reduction of his immunosuppressive therapy. IRIS appeared concomitantly with a dramatic increase of blood CD4+ T cells (94,460/mm3) and required the administration of a short-term steroid therapy to resolve. [source] JC virus persistence following progressive multifocal leukoencephalopathy in multiple sclerosis patients treated with natalizumab,ANNALS OF NEUROLOGY, Issue 3 2010Caroline F. Ryschkewitsch MT JC virus (JCV) DNA in the cerebrospinal fluid (CSF) provides the laboratory confirmatory diagnosis of progressive multifocal leukoencephalopathy (PML) in patients whose clinical symptoms and magnetic resonance imaging findings are consistent with PML. The Laboratory of Molecular Medicine and Neuroscience (LMMN), National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), made the confirmatory laboratory diagnosis in 35 multiple sclerosis (MS) patients treated with natalizumab. Thirteen patients had 3 or more CSF samples taken from weeks to months following PML diagnosis. Seven of the 13 patients demonstrated persistence of JCV DNA in the CSF even though all patients experienced immune reconstitution inflammatory syndrome (IRIS), 11 patients had plasma exchange, and 2 had immunoabsorption. Specific anti-JCV antibody was measured in plasma/sera samples from 25 of the 35 patients. Most of the samples showed moderate to high or rising antibody levels from the time of PML diagnosis. However, plasma from 1 patient at or near the time of PML diagnosis had a titer considered seronegative and 2 other plasma samples from patients had titers considered at baseline for seropositivity. In several PML cases, viral persistence and neurological deficits have continued for several years, indicating that once initiated, JCV infection may not entirely clear, even with IRIS. Ann Neurol 2010;68:384,391 [source] Efficacy of imatinib dose escalation in patients with chronic myeloid leukemia in chronic phase,,§CANCER, Issue 3 2009Hagop M. Kantarjian MD Abstract BACKGROUND: Imatinib mesylate given orally at a daily dose of 400 mg is the standard of care as initial therapy for patients with chronic myeloid leukemia (CML) in chronic phase (CML-CP). Treatment guidelines propose dose escalation based on clinical assessments of disease response. METHODS: Response and survival were analyzed in a cohort of patients (n = 106) with newly diagnosed CML-CP who were enrolled on the International Randomized Study of Interferon and STI571 (IRIS) trial, who began treatment with imatinib at a dose of 400 mg daily, and who subsequently underwent dose escalation to either 600 mg or 800 mg daily. Reasons for dose escalation were evaluated retrospectively based on 2 sets of criteria: the IRIS protocol-defined criteria (n = 39 patients) and the European LeukemiaNet (ELN) recommendations (n = 48 patients). RESULTS: Among all 106 patients who underwent dose escalation, the rates of freedom from progression to accelerated phase or blast phase and overall survival were 89% and 84% at 3 years after dose increase, respectively. A cytogenetic response was obtained in 42% of patients who had their dose escalated based on protocol criteria and in 38% of patients who had their dose escalated according to the ELN recommendations. CONCLUSIONS: The results from this retrospective analysis supported imatinib dose escalation as an appropriate initial option for patients with CML-CP who were experiencing suboptimal cytogenetic response or resistance. Cancer 2009. © 2008 American Cancer Society. [source] Long-term survival estimates for imatinib versus interferon-, plus low-dose cytarabine for patients with newly diagnosed chronic-phase chronic myeloid leukemia,,CANCER, Issue 11 2004Kevin J. Anstrom Ph.D. Abstract BACKGROUND The authors estimated survival among patients with chronic myeloid leukemia for a cost-effectiveness analysis of imatinib versus interferon-, plus low-dose cytarabine (IFN+LDAC). METHODS Two-year survival and cytogenetic response were determined using data from 553 patients who received first-line imatinib in the International Randomized Interferon versus ST571 Study (IRIS). Long-term survival was modeled on complete cytogenetic response (CCyR) after 2 years. Long-term survival for patients with a CCyR was modeled using data from a cohort study of 317 patients with CCyRs. Long-term survival for patients without a CCyR was modeled using data from a trial of 275 patients who were treated with IFN+LDAC. Computation of lifetime survival estimates for imatinib assumed a proportional hazards relation between survival for an age-matched and gender-matched cohort and survival for patients with and without a CCyR. RESULTS For IRIS patients receiving imatinib, the estimated survival was 95.8% and the CCyR rate was 73.8%. The average residual life expectancy was estimated to be 16.71 years for CCyR patients and 5.78 years for non-CCyR patients. The estimated life expectancy after treatment with imatinib was 15.30 years, compared with 9.07 years for patients who were treated with IFN+LDAC in previous studies. CONCLUSIONS Assuming the relation between CCyR and survival with interferon-, holds for imatinib, higher CCyR rates with imatinib therapy will result in an estimated 6.23 life-years gained compared with treatment with IFN+LDAC. Cancer 2004. © 2004 American Cancer Society. [source] First experience with The IRIS retinal implant systemACTA OPHTHALMOLOGICA, Issue 2009M VELIKAY-PAREL Purpose To report on the first 4 months experience of a patient with the active IRIS- Implant. Methods 4 weeks after implantation the training with the active implant started. Thresholds were measured at each training day. Light perception, light localisation, point to point discrimination and motion detection were measured with special test procedures. Visual function training was performed. Results Visual perception was achieved, when the stimuli were generated by the computer and with the camera mode. All tests were successful. Conclusion Successful stimulation and major improvements during the training demonstrates that with the Iris Implant System a visual perception can be achieved, which is relevant for daily life. [source] Iris as a recipient tissue for pigment cells: Organized in vivo differentiation of melanocytes and pigmented epithelium derived from embryonic stem cells in vitroDEVELOPMENTAL DYNAMICS, Issue 9 2008Hitomi Aoki Abstract Regenerative transplantation of embryonic stem (ES) cell-derived melanocytes into adult tissues, especially skin that includes hair follicles or the hair follicle itself, generally not possible, whereas that of ES cell-derived pigmented epithelium was reported previously. We investigated the in vivo differentiation of these two pigment cell types derived from ES cells after their transfer into the iris. Melanocytes derived from ES cells efficiently integrated into the iris and expanded to fill the stromal layer of the iris, like those prepared from neonatal skin. Transplanted pigmented epithelium from either ES cells or the neonatal eye was also found to be integrated into the iris. Both types of these regenerated pigment cells showed the correct morphology. Regenerated pigment epithelium expressed its functional marker. Functional blocking of signals required for melanocyte development abolished the differentiation of transplanted melanocytes. These results indicate successful in vivo regenerative transfer of pigment cells induced from ES cells in vitro. Developmental Dynamics 237:2394,2404, 2008. © 2008 Wiley-Liss, Inc. [source] In Memory of IrisHYPATIA, Issue 3 2008JOHN MURUNGI No abstract is available for this article. [source] The Pigmentation of Human Iris Influences the Uptake and Storing of ZincPIGMENT CELL & MELANOMA RESEARCH, Issue 5 2004Despina Kokkinou Age-related macular degeneration (AMD) is more prevalent among the elderly Caucasians than in Africans. A significant association between light iris colour, fundus pigmentation and incidence of AMD is reported, suggesting a possible correlation with melanin pigment. Zinc is known to bind to melanin in pigmented tissues and to enhance antioxidant capacity by function as a cofactor or gene expression factor of antioxidant enzymes in the eye. In this in vitro study, we investigated the uptake and storage of zinc in human irides. Irides of blue and brown human eyes were used. The number of melanocytes was measured. Tissues without any treatment served as controls. The irides were incubated with 100 ,M zinc chloride in culture medium for 24 h. Specimens of the tissues were stored for the uptake examination. The remained pieces were further incubated for 3 and 7 d to investigate the storage of zinc. The concentration of zinc was measured by inductively coupled plasma mass spectrometry (ICP-MS). Melanocytes count was significantly higher in the brown tissues (P < 0.0001). Zinc concentration of blue coloured irides after 24 h zinc treatment was close to the controls. We did not observe any significant storing. In contrast, the concentration of zinc in brown irides was significantly increased after 24 h (P , 0.01) and remained at a high level for 7 d. The uptake of zinc is likely dependent on the amount of pigmentation in human iris. Therefore, we assume that in patients suffering from AMD the degree of pigmentation of the irides and eventually fundi should be under consideration when the patients are treated with zinc supplementation. [source] The Effect of Hurricane Iris on the Food Supply of Black Howlers (Alouatta pigra) in Southern Belize1BIOTROPICA, Issue 1 2005Mary S. M. Pavelka ABSTRACT Hurricanes frequently affect the forests of South and Central America; however, few studies have quantified their effects to forest structure, especially when concentrating on the food supply of an animal population. Hurricane Iris made landfall in Southern Belize on 8 October 2001, severely damaging a 52 hectare site where the behavioral ecology of a population of Central American Black Howlers (Alouatta pigra) had been under study for 2.5 yr. The hurricane resulted in a mortality rate of 35 percent for major food trees, which was primarily attributed to uprooting, snapping, and major delimbing. This damage accounted for 97 percent of the food tree loss between the two sample periods. Tree species differences were found in both the percentage loss and category of damage to food trees. Trees of different heights also experienced different percentage loss and levels of damage; subcanopy and emergent trees experienced higher loss than canopy trees, and subcanopy trees were frequently uprooted. This was partially attributed to a lack of buttressing on these subcanopy trees. Buttressing was found to decrease the frequency of uprooting. Tree size was the only factor that did not influence either damage or death. Trees from which fruit were eaten by black howlers died more than twice as often as did trees eaten for leaves. [source] Nd:YAG laser goniopuncture after deep sclerectomy: outcomesACTA OPHTHALMOLOGICA, Issue 1 2010Nitin Anand Abstract. Purpose:, This study aimed to investigate the safety and efficacy of Nd:YAG laser goniopuncture (LGP) in lowering intraocular pressure (IOP) after deep sclerectomy (DS). Methods:, We reviewed the outcomes in 258 eyes of 258 consecutive patients who underwent DS or combined phacoemulsification and DS between August 2001 and December 2003. Mitomycin C was used during surgery in 192 eyes (74.4%). Results:, Mean follow-up was 40 ± 11 months after DS and 31 ± 12 months after LGP. Laser goniopuncture was performed in 173 eyes (67.0%). The mean interval between LGP and DS was 10.3 ± 8.7 months. The probability of LGP being performed was 63.1% (95% confidence interval [CI] 57.3,69.4) at 36 months after surgery. At 2 years after LGP, the probability of maintaining IOP < 15 mmHg with a 20% decrease from the pre-laser IOP and no further glaucoma procedure or medication was 49.7% (95% CI 41.9,57.1). Iris covering the trabeculo-Descemet's membrane was the only factor significantly associated with the failure of LGP (hazard ratio 3.0, p < 0.001). Complications observed after LGP included peripheral anterior synechiae in 23 (13.2%), hypotony in seven (4.0%), late acute IOP rise in three (1.7%), delayed bleb leak in one and blebitis in two eyes. Argon laser iridoplasty was performed in 45 (26.0%) and needle revision in 41 (23.7%) eyes. Conclusions:, ND:YAG laser goniopuncture is an effective procedure to further lower IOP after DS. An IOP of < 15 mmHg is achieved and maintained for , 2 years in about 50% of cases after a single LGP procedure. There are potentially serious complications associated with the procedure. Regular gonioscopy is recommended following LGP to detect any occlusion of the goniopuncture by the iris. [source] Treating the dementia of ,Iris' with a cholinesterase inhibitorINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 4 2003Peter J. Connelly No abstract is available for this article. [source] Identification of genes expressed preferentially in the developing peripheral margin of the optic cupDEVELOPMENTAL DYNAMICS, Issue 9 2009Jeffrey M. Trimarchi Abstract Specification of the peripheral optic cup by Wnt signaling is critical for formation of the ciliary body/iris. Identification of marker genes for this region during development provides a starting point for functional analyses. During transcriptional profiling of single cells from the developing eye, two cells were identified that expressed genes not found in most other single cell profiles. In situ hybridizations demonstrated that many of these genes were expressed in the peripheral optic cup in both early mouse and chicken development, and in the ciliary body/iris at subsequent developmental stages. These analyses indicate that the two cells probably originated from the developing ciliary body/iris. Changes in expression of these genes were assayed in embryonic chicken retinas when canonical Wnt signaling was ectopically activated by CA-,-catenin. Twelve ciliary body/iris genes were identified as upregulated following induction, suggesting they are excellent candidates for downstream effectors of Wnt signaling in the optic cup. Developmental Dynamics 238:2327,2339, 2009. © 2009 Wiley-Liss, Inc. [source] Ocular Complication of PhotoDerm VL Therapy for Facial Port-Wine StainDERMATOLOGIC SURGERY, Issue 1 2003Florian K. P Sutter MD BACKGROUND A case of focal damage to the iris with distortion of the pupil secondary to PhotoDerm therapy in a 2-year-old boy is reported. OBJECTIVE To study ocular complication of photoDerm VL therapy for facial port-wine stain. METHODS Observatory case report. RESULTS. PhotoDerm VL therapy may damage ocular tissues. CONCLUSION Appropriate protection during the procedure is essential. [source] Iris as a recipient tissue for pigment cells: Organized in vivo differentiation of melanocytes and pigmented epithelium derived from embryonic stem cells in vitroDEVELOPMENTAL DYNAMICS, Issue 9 2008Hitomi Aoki Abstract Regenerative transplantation of embryonic stem (ES) cell-derived melanocytes into adult tissues, especially skin that includes hair follicles or the hair follicle itself, generally not possible, whereas that of ES cell-derived pigmented epithelium was reported previously. We investigated the in vivo differentiation of these two pigment cell types derived from ES cells after their transfer into the iris. Melanocytes derived from ES cells efficiently integrated into the iris and expanded to fill the stromal layer of the iris, like those prepared from neonatal skin. Transplanted pigmented epithelium from either ES cells or the neonatal eye was also found to be integrated into the iris. Both types of these regenerated pigment cells showed the correct morphology. Regenerated pigment epithelium expressed its functional marker. Functional blocking of signals required for melanocyte development abolished the differentiation of transplanted melanocytes. These results indicate successful in vivo regenerative transfer of pigment cells induced from ES cells in vitro. Developmental Dynamics 237:2394,2404, 2008. © 2008 Wiley-Liss, Inc. [source] Assortative mating between adjacent populations of threespine stickleback (Gasterosteus aculeatus)ECOLOGY OF FRESHWATER FISH, Issue 1 2004R. J. Scott Abstract,,, The idea that sexual selection can lead to rapid evolution of premating isolation among independent populations (speciation) has been controversial, but is rapidly gaining acceptance among many evolutionary biologists as empirical examples accumulate. A survey of male signals and female preferences (mate recognition systems, MRSs) across the contact zone between divergent populations of threespine stickleback (Gasterosteus aculeatus) in Conner Creek, WA, revealed a spatial pattern of MRSs that is consistent with speciation via sexual selection. Females from locations that possessed melanic males preferred melanic males whereas females from populations possessing typical mosaic males (red chin, blue iris, and blue-green dorsum) preferred mosaic males. I argue that sensory drive sexual selection, acting through geographically varying spectral properties, is responsible for the observed population differences and premating isolation between the adjacent populations. [source] Acute and chronic toxicity of mercury to early life stages of the rainbow mussel, Villosa iris (Bivalvia: Unionidae)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2005Theodore W. Valenti Abstract Mercury (Hg) contamination is receiving increased attention globally because of human health and environmental concerns. Few laboratory studies have examined the toxicity of Hg on early life stages of freshwater mussels, despite evidence that glochidia and juvenile life stages are more sensitive to contaminants than adults. Three bioassays (72-h acute glochidia, 96-h acute juvenile, and 21-d chronic juvenile toxicity tests) were conducted by exposing Villosa iris to mercuric chloride salt (HgCl2). Glochidia were more sensitive to acute exposure than were juvenile mussels, as 24-, 48-, and 72-h median lethal concentration values (LC50) for glochidia were >107, 39, and 14 ,g Hg/L, respectively. The 24-, 48-, 72-, and 96-h values for juveniles were 162, 135, 114, and 99 ,g Hg/L, respectively. In the chronic test, juveniles exposed to Hg treatments ,8 ,g/L grew significantly less than did control organisms. The substantial difference in juvenile test endpoints emphasizes the importance of assessing chronic exposure and sublethal effects. Overall, our study supports the use of glochidia as a surrogate life stage for juveniles in acute toxicity tests. However, as glochidia may be used only in short-term tests, it is imperative that an integrated approach be taken when assessing risk to freshwater mussels, as their unique life history is atypical of standard test organisms. Therefore, we strongly advocate the use of both glochidia and juvenile life stages for risk assessment. [source] The role of NGF uptake in selective vulnerability to cell death in ageing sympathetic neuronsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2004Kliment P. Gatzinsky Abstract We have examined the hypothesis that differences in nerve growth factor (NGF) uptake and transport determine vulnerability to age-related neurodegeneration. Neurons projecting to cerebral blood vessels (CV) in aged rats are more vulnerable to age-related degeneration than those projecting to the iris. Uptake of NGF was therefore examined in sympathetic neurons projecting from the superior cervical ganglion (SCG) to CV and iris in young and old rats by treating the peripheral processes of these neurons with different doses of I125 -NGF. Total uptake of I125 -NGF was reduced in old CV-projecting, but not iris-projecting, neurons. Numbers of radiolabelled neurons projecting to each target were counted in sectioned ganglia. The data showed age-related reductions in numbers of labelled neurons projecting to CV, but no change in numbers of neurons projecting to the iris. Calculation of uptake of I125 -NGF per neuron unexpectedly showed no major age-related differences in either of the two neuron populations. However, uptake per neuron was considerably lower for young and old CV-projecting, compared to iris-projecting, SCG neurons. We hypothesized that variations in NGF uptake might affect neuronal survival in old age. Counts of SCG neurons using a physical disector following retrograde tracing with Fluorogold confirmed the selective vulnerability of CV-projecting neurons by showing a significant 37% loss of these neurons in the period between 15 and 24 months. In contrast, there was no significant loss of iris-projecting neurons. We conclude that vulnerability to, or protection from, age-related neurodegeneration and neuronal cell death are associated with life-long low, or high, levels of NGF uptake, respectively. [source] New Cells for the Human RetinaGERMAN RESEARCH, Issue 2-3 2002Gabriele Thumann PD Dr. Age-dependent damage to the retina can lead to blindness. It may be possible to restore vision by transplanting cells from the iris onto the retina [source] A case of Adamantiades-Behçet disease with ischemic optic neuritis (posterior optic neuropathy)JOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 11 2007Satoko Shima Summary Adamantiades-Behçet disease (ABD) may present with cutaneous and ophthalmologic finings. A 29-year old woman complained of fever and general fatigue, along with erythema nodosum and vesiculo-pustular lesions on the legs, acneiform lesions, genital ulcerations and painful oral ulcers. She also complained of reduced visual acuity, visual disturbance and blurred vision in the left eye. Her left visual acuity was 6/20. Light reflex in the left eye was reduced. The relative afferent pupillary defect (RAPD) was positive in the left eye where a central scotoma was present. The vitreous was clear; the optic disc, macula, retina and iris were all normal. Uveitis was not observed. The patient was diagnosed with ischemic optic neuritis (posterior optic neuropathy) with ABD. Histopathological findings taken from a blister on the leg showed subepidermal bulla, dense dermal neutrophil infiltration, and extravasation of erythrocytes, suggesting leukocytoclastic vas-culitis. She was treated orally with high-dose corticosteroids (methylprednisolone 500 mg/d) for three days. Her general condition and ophthalmic symptoms resolved completely. Optic neuropathy with ABD is very rare; we know of two previous cases [1, 2] of ABD with ischemic posterior optic neuritis. [source] Regeneration, tissue injury and the immune responseJOURNAL OF ANATOMY, Issue 4 2006James W. Godwin Abstract The involvement of the immune system in the response to tissue injury has raised the possibility that it might influence tissue, organ or appendage regeneration following injury. One hypothesis that has been discussed is that inflammatory aspects may preclude the occurrence of regeneration, but there is also evidence for more positive roles of immune components. The vertebrate eye is an immunoprivileged site where inflammatory aspects are inhibited by several immunomodulatory mechanisms. In various newt species the ocular tissues such as the lens are regenerative and it has recently been shown that the response to local injury of the lens involves activation of antigen-presenting cells which traffic to the spleen and return to displace and engulf the lens, thereby inducing regeneration from the dorsal iris. The activation of thrombin from prothrombin in the dorsal iris is one aspect of the injury response that is important in the initiation of regeneration. The possible relationships between the immune response and the regenerative response are considered with respect to phylogenetic variation of regeneration in general, and lens regeneration in particular. [source] Secrets in the eyes of Black Oystercatchers: a new sexing techniqueJOURNAL OF FIELD ORNITHOLOGY, Issue 2 2008Brian M. Guzzetti ABSTRACT Sexing oystercatchers in the field is difficult because males and females have identical plumage and are similar in size. Although Black Oystercatchers (Haematopus bachmani) are sexually dimorphic, using morphology to determine sex requires either capturing both pair members for comparison or using discriminant analyses to assign sex probabilistically based on morphometric traits. All adult Black Oystercatchers have bright yellow eyes, but some of them have dark specks, or eye flecks, in their irides. We hypothesized that this easily observable trait was sex-linked and could be used as a novel diagnostic tool for identifying sex. To test this, we compared data for oystercatchers from genetic molecular markers (CHD-W/CHD-Z and HINT-W/HINT-Z), morphometric analyses, and eye-fleck category (full eye flecks, slight eye flecks, and no eye flecks). Compared to molecular markers, we found that discriminant analyses based on morphological characteristics yielded variable results that were confounded by geographical differences in morphology. However, we found that eye flecks were sex-linked. Using an eye-fleck model where all females have full eye flecks and males have either slight eye flecks or no eye flecks, we correctly assigned the sex of 117 of 125 (94%) oystercatchers. Using discriminant analysis based on morphological characteristics, we correctly assigned the sex of 105 of 119 (88%) birds. Using the eye-fleck technique for sexing Black Oystercatchers may be preferable for some investigators because it is as accurate as discriminant analysis based on morphology and does not require capturing the birds. SINOPSIS El sexado de ostreros en el campo es sumamente difícil dado el caso de que tanto hembras como machos tienen plumaje idéntico y son similares en tamaño. Aunque los ostreros negros (Haematopus bachmani) son sexualmente dimórficos, el utilizar morfometría para determinar su sexo requiere capturar a ambos miembros de la pareja para compararlos, utilizando una análisis discriminativo a modo de asignar un sexo por probabilidad, basado en características morfométricas. Todos los adultos del ostrero negro tienen ojos amarillos y brillantes, pero algunos tienen manchas oscuras en el iris. Tomamos como hipótesis que estas peculiaridades observables estaban ligada al sexo, y que podían ser utilizadas como una herramienta novel de diagnóstico para identificar el sexo en dichas aves. Para poner a pruebas lo mencionado, comparamos datos de ostreros donde se utilizaron marcadores genéticos moleculares (CHD-W/CHD-Z y HINT-W/HINT-Z), análisis morfométrico, y categorías en las manchas en los ojos (manchas marcadas en los ojos, algunas manchitas en los ojos, sin manchas en los ojos). Comparado a marcadores moleculares, encontramos que el análisis discriminativo basado en características morfológicas ofrecía resultados variables asociados a diferencias morfológicas geográficas. Sin embargo, encontramos que las manchas en los ojos estaban ligadas al sexo. Utilizando un modelo de manchas en los ojos, en donde clasificamos como hembras aquellos individuos con manchas pronunciadas en los ojos y a machos con muy pocas manchitas o sin manchitas, le pudimos asignar correctamente el sexo a 117 de 125 (94%) individuos. Utilizando una análisis discriminativo basado en características morfológicas, le asignamos el sexo correctamente a 105 de 119 (88%) individuos. El utilizar la técnica de manchas en los ojos para el sexado de ostreros negros pudiera ser preferible para algunos investigadores porque es más exacto que el análisis discriminativo basado en morfología y porque no requiere que se tenga que capturar a las aves. [source] Reduced age-related plasticity of neurotrophin receptor expression in selected sympathetic neurons of the ratAGING CELL, Issue 1 2003T. Cowen Summary Selective vulnerability of particular groups of neurons is a characteristic of the aging nervous system. We have studied the role of neurotrophin (NT) signalling in this phenomenon using rat sympathetic (SCG) neurons projecting to cerebral blood vessels (CV) and iris which are, respectively, vulnerable to and protected from atrophic changes during old age. RT-PCR was used to examine NT expression in iris and CV in 3- and 24-month-old rats. NGF and NT3 expression in iris was substantially higher compared to CV; neither target showed any alterations with age. RT-PCR for the principal NT receptors, trkA and p75, in SCG showed increased message during early postnatal life. However, during mature adulthood and old age, trkA expression remained stable while p75 declined significantly over the same period. In situ hybridization was used to examine receptor expression in subpopulations of SCG neurons identified using retrograde tracing. Eighteen to 20 h following local treatment of iris and CV with NGF, NT3 or vehicle, expression of NT receptor protein and mRNA was higher in iris- compared with CV-projecting neurons from both young and old rats. NGF and NT3 treatment had no effect on NT receptor expression in CV-projecting neurons at either age. However, similar treatment up-regulated p75 and trkA expression in iris-projecting neurons from 3-month-old, but not 24-month-old, rats. We conclude that lifelong exposure to low levels of NTs combined with impaired plasticity of NT receptor expression are predictors of neuronal vulnerability to age-related atrophy. [source] | ||||||||||||||||||||||||||||||||||