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PubMed2003

[Prevalence and risk factors of age-related maculopathy among middle aged people].

OBJECTIVE: To investigate the prevalence of age-related maculopathy and the relationships of age-related maculopathy to age, sex, ocular factors, education, work exposures. A population-based cohort study included 1357 subjects (35-64 years of age) living in Kaunas (Lithuania), who were examined during the interval from 2001 to 2002. The diagnosis of age-related maculopathy was based on ophthalmoscopic findings or on fundus photographs. The prevalence of early age-related maculopathy was 7.3% in persons 40-64 years of age. No late age-related maculopathy (AMD) was found. Prevalence of early age-related maculopathy was strongly related to age (P<0.001). No significant prevalence differences were between the sexes. The frequency of age-related maculopathy was higher in eyes with light iris color but association was not significant. No associations were found between cataract or cataract type and ARM. There was no association between education and age-related maculopathy. Exposure to harmful work was found to be related to the presence of early age-related maculopathy in all. The prevalence of age-related maculopathy was significantly higher between men working in high temperature.

Adult↗
PubMed1964

KOELLNER EFFECT AND SUPPRESSION OF THE VIEW OF AN EYE.

Köllner's discovery of binasal hemianopia as an early stage in binocular color rivalry is extended to the study of the subsequent suppression of the color seen by an eye. The Köllner effect is one of the five two-color configurations that occur initially, and through which total suppression develops by the visible expansion of one of the colors. However, suppression sometimes occurs without a two-color phase.

Biomedical Research↗
PubMed1979

Developmental changes of sepiapterin synthase activity associated with a variegated purple gene in Drosophila melanogaster.

A variegated position effect on the autonomous gene, purple, has been studid enzymologically in Drosophila melanogaster. Sepiapterin synthase, the enzyme system associated with pr+, was examined for activity in different developmental stages of the fly. The results indicate that T(y:22)prc5, cn/prc4 cn flies (flies in which pr+ has been translocated and which exhibit variegation) have a reduced amount of enzyme activity as compared with both Oregon-R and pr1 flies. This reduction in activity was not found in larval stages, which suggests that the inactivation process probably occurs in late larval or early pupal stages. The phenotype of the variegated adult has white eyes with red-colored spots and patches where drosopterins occur. The phenotype of the fly carrying the translocation is modified by the presence of additional Y chromosomes. This extends the observation from other systems that extra heterochromatin acts to suppress the variegated position effect. The advantages of studying the variegation by measuring enzyme activity, as well as the phenotypic expression, are several; for example, the developmental time at which variegation occurs may be estimated even though drosopterin synthesis is not occurring.

Animals↗
PubMed1991

The effect of ractopamine hydrochloride on the carcass cutting yields of finishing swine.

This study was designed to evaluate growth performance, carcass cutting yield, and processing characteristics of boneless hams and bellies from finishing pigs fed diets containing 0, 5, 10, or 20 ppm of the phenethanolamine ractopamine hydrochloride (RAC). Sixty pigs were blocked by starting weight and randomly assigned to pens (four pigs/pen) within each of three blocks. Treatments were then randomly assigned to the pens to total six pens of the 0-ppm level and three pens each at the 5-, 10-, and 20-ppm RAC levels. Weight gain and feed consumption were monitored and animals were slaughtered by weight block after approximately 48 d on trial. Slaughter weight, ADG, and feed/gain were improved (P less than .05) for RAC treatments. Dressing percentage was higher and increased linearly (P less than .05) for RAC treatments. Carcass weight, length, leaf fat weight, backfat thickness, loin eye area, and color, marbling, and firmness of the longissimus were evaluated. The RAC-treated carcasses were heavier (P less than .05) and loin eye area increased linearly (P less than .05). One side of each carcass was fabricated using National Association of Meat Purveyors specifications. Trimmed hams and loins from the RAC treatments were heavier (P less than .05) than those from control animals. No differences (P greater than .05) in carcass cutting yield (percentage of trimmed primal cuts) were observed between treatments. However, trimmed hams and loins from the 20-ppm RAC treatment represented a greater (P less than .05) percentage of carcass weight than did those from control animals. Ractopamine did not affect raw belly or bacon characteristics (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1997

Serotonin-induced constriction of ocular arteries in atherosclerotic monkeys. Implications for ischemic disorders of the retina and optic nerve head.

BACKGROUND: Ischemic disorders of the retina and optic nerve head, which constitute a common cause of visual loss, are usually seen in patients with atherosclerosis. OBJECTIVE: To test the hypothesis that serotonin, which is released when platelets aggregate, may produce vasospasm in atherosclerotic monkeys and, thus, may contribute to the ischemic disorders and that short-term dietary treatment of atherosclerosis causes the propensity to vasospasm to subside. METHODS: We studied the response of retinal and posterior ciliary circulation to serotonin in 18 atherosclerotic (25 eyes) and 5 normal (8 eyes) cynomolgus monkeys. The eyes were evaluated by color fundus photography and fluorescein fundus angiography. The eyes were examined under basal conditions and, at a different time, during the intravenous infusion of serotonin. In 6 of the 18 atherosclerotic animals, the evaluation was repeated 5 to 12 months after discontinuing the atherogenic diet (ie, the regression group). RESULTS: Serotonin had no effect in normal monkeys. In 18 atherosclerotic monkeys, serotonin produced transient occlusion or delayed filling of the central retinal artery and/or posterior ciliary artery (PCA) in 9 eyes of 9 animals, involving the central retinal artery in 5, lateral PCA in 8, and medial PCA in 5, in various combinations. In 6 animals (6 eyes) of the regression group, the vasoconstrictor effect of serotonin was abolished completely, except in the medial PCA in 1 eye. CONCLUSIONS: Serotonin, in the presence of atherosclerotic lesions, can cause transient, complete occlusion or impaired blood flow in the central retinal artery and/or PCA. We speculate that this mechanism may play a role in the development of ischemic disorders of the retina and optic nerve head. Discontinuing the atherogenic diet abolished or markedly improved the serotonin-induced vasoconstriction within a few months.

Animals↗
PubMed1998

Stable transformation of the yellow fever mosquito, Aedes aegypti, with the Hermes element from the housefly.

The mosquito Aedes aegypti is the world's most important vector of yellow fever and dengue viruses. Work is currently in progress to control the transmission of these viruses by genetically altering the capacity of wild Ae. aegypti populations to support virus replication. The germ-line transformation system reported here constitutes a major advance toward the implementation of this control strategy. A modified Hermes transposon carrying a 4.7-kb fragment of genomic DNA that includes a wild-type allele of the Drosophila melanogaster cinnabar (cn) gene was used to transform a white-eyed recipient strain of Ae. aegypti. Microinjection of preblastoderm mosquito embryos with this construct resulted in 50% of the emergent G0 adults showing some color in their eyes. Three transformed families were recovered, each resulting from an independent insertion event of the cn+-carrying transposon. The cn+ gene functioned as a semidominant transgene and segregated in Mendelian ratios. Hermes shows great promise as a vector for efficient, heritable, and stable transformation of this important mosquito vector species.

Aedes↗
PubMed1991

[Color vision defects of macular diseases].

Patients with macular diseases such as x-linked juvenile retinoschisis, cone dystrophy, and age-related macular degeneration were studied regarding color vision defects. In 9 of 15 eyes of patients with x-linked juvenile retinoschisis, blue-yellow defects were demonstrated. In the older patients with this dystrophy, color vision defects were more severe than in younger ones. Fluorescein angiography revealed retinal pigment epithelium (RPE) atrophy at the macular area in these older patients. Therefore, it was suggested that the color vision defects were due to dysfunction of the outer sensory retina, occurring secondarily to the inner sensory retina. In patients with cone dystrophy, all the examined eyes showed severe color vision defects. It was proved that the size of the atrophic lesion which when ophthalmoscopically evaluated was found to have some relationship with the degree of color vision defects. In patients with age-related macular degeneration, most of the examined eyes showed color vision defects. Moreover eyes with soft drusen formation and/or RPE detachment usually showed more severe color vision defects than the eyes with hard drusen formation and/or RPE atrophy.

Adolescent↗
PubMed1988

Histocompatibility antigen changes associated with pink-eyed dilute (p) mutations.

The tight linkage between the H-4 histocompatibility locus and the pink-eyed dilute (p) locus raises the possibility that a single gene is responsible for both a histocompatibility antigen and coat color phenotype. To examine this possibility, we have investigated the effects of a spontaneous coat color mutation, pink-eyed unstable (pun), which occurred at the p locus in the C57BL/6J inbred strain, on histocompatibility antigen phenotype. Skin grafts were transplanted from two independently maintained B6-pun substrains to coisogenic, wild-type C57BL/6 recipients; graft rejection uniformly commenced at 6-7 weeks but did not culminate in complete graft destruction as observed in other cases of "crisis" rejection. Neither the onset of rejection time nor the intensity of rejection could be accelerated by introducing new H-2 haplotypes into the wild-type recipients. These results suggested that the pun allele was associated with a histocompatibility antigen not shared with C57BL/6. The pun allele is characterized by a relatively high frequency of reversion to wild-type. Therefore, skin grafts from B6-pun donors were transplanted to homozygous, revertant (+/+) recipients which were subline-matched with the donors; these grafts underwent crisis rejection with the same time of onset of rejection as observed with C57BL/6 recipients. These observations indicate that a new histocompatibility antigen is associated with the pun mutation and is lost upon reversion to wild type; this association is the first demonstration of a link between histocompatibility and coat color phenotypes.

Animals↗
PubMed2003

The relationship between iris color, hair color, and skin sun sensitivity and the 10-year incidence of age-related maculopathy: the Beaver Dam Eye Study.

PURPOSE: To examine the association between iris color, hair color, and skin sun sensitivity and the 10-year incidence of age-related maculopathy (ARM). DESIGN: Population-based cohort study. PARTICIPANTS: A population of 4926 adults (range, 43-86 years of age at baseline) living in Beaver Dam, Wisconsin, was studied at baseline (1988-1990); of these, 3684 and 2764 subjects, respectively, participated in 5-year and 10-year follow-up examinations. METHODS: Data on hair color at age 15 years and skin responsiveness to sun exposure were obtained from a standardized questionnaire administered at the baseline examination. Iris color was determined with penlight illumination during the baseline examination by using photographic standards. Age-related maculopathy status was determined by grading stereoscopic color fundus photos with the Wisconsin Age-Related Maculopathy Grading System. MAIN OUTCOME MEASURES: Incidence and progression of ARM. RESULTS: When controlling for age and gender, people with brown eyes were significantly more likely to develop soft indistinct drusen (risk ratio [RR], 1.53; 95% confidence interval [CI], 1.19-1.97; P < 0.01) than were people with blue eyes. However, people with brown eyes were significantly less likely to develop retinal pigment epithelial depigmentation (RR, 0.58; 95% CI, 0.41-0.82; P < 0.01) than were people with blue eyes. When compared with persons with blond hair, persons with brown hair were at decreased risk of developing pigmentary abnormalities (RR, 0.73; 95% CI, 0.53-1.00; P = 0.05). Iris color, hair color, and skin sun sensitivity were not associated with the development of late ARM. CONCLUSION: Iris color and hair color were found to be associated with the 10-year incidence of pigmentary abnormalities. Iris color seems to be inconsistently related to the 10-year incidence of early ARM lesions and the progression of ARM.

Adult↗
PubMed2000

Latanoprost-induced iris color darkening: a case report with long-term follow-up.

PURPOSE: To determine the effect on iris color of discontinuing latanoprost (LP) treatment in a patient with pronounced iris color darkening, and to assess the possible role of sympathetic innervation. METHODS: In a patient demonstrating pronounced iris color darkening in both eyes after treatment with LP for 6 months, magnified iris color photographs were taken at 3- to 6-month intervals for 5 years after discontinuation of LP treatment. Pupillary testing for sympathetic insufficiency was performed with cocaine 10% or hydroxyamphetamine 1%. RESULTS: The iris color did not appreciably change after discontinuing LP. The cocaine-induced increase in pupillary diameter was considerably greater for the control subject than for the patient who demonstrated the LP-induced color change. CONCLUSIONS: Latanoprost-induced iris color darkening does not appreciably change for several years after discontinuing treatment. Some eyes that show LP-induced darkening may have relative ocular sympathetic insufficiency.

Antihypertensive Agents↗
PubMed2003

Neuroarchitecture of the color and polarization vision system of the stomatopod Haptosquilla.

The apposition compound eyes of stomatopod crustaceans contain a morphologically distinct eye region specialized for color and polarization vision, called the mid-band. In two stomatopod superfamilies, the mid-band is constructed from six rows of enlarged ommatidia containing multiple photoreceptor classes for spectral and polarization vision. The aim of this study was to begin to analyze the underlying neuroarchitecture, the design of which might reveal clues how the visual system interprets and communicates to deeper levels of the brain the multiple channels of information supplied by the retina. Reduced silver methods were used to investigate the axon pathways from different retinal regions to the lamina ganglionaris and from there to the medulla externa, the medulla interna, and the medulla terminalis. A swollen band of neuropil-here termed the accessory lobe-projects across the equator of the lamina ganglionaris, the medulla externa, and the medulla interna and represents, structurally, the retina's mid-band. Serial semithin and ultrathin resin sections were used to reconstruct the projection of photoreceptor axons from the retina to the lamina ganglionaris. The eight axons originating from one ommatidium project to the same lamina cartridge. Seven short visual fibers end at two distinct levels in each lamina cartridge, thus geometrically separating the two channels of polarization and spectral information. The eighth visual fiber runs axially through the cartridge and terminates in the medulla externa. We conclude that spatial, color, and polarization information is divided into three parallel data streams from the retina to the central nervous system.

Animals↗