Age-related differences in lexical access, spreading activation, and simple pronunciation.

An experiment was conducted to address age-related differences in lexical access, spreading activation, and pronunciation. Both young and older adults participated in a delayed pronunciation task to trace the time course of lexical access and a semantic priming task to trace the time course of spreading activation. In the delayed pronunciation task, subjects were presented a word and then, after varying delays, were presented a cue to pronounce the word aloud. Older adults benefited considerably more from the preexposure to the word than did the younger adults, suggesting an age-related difference in lexical access time. In the semantic priming pronunciation task, semantic relatedness (related vs. neutral), strength of the relationship (high vs. low), and prime–target stimulus onset asynchrony (200 ms, 350 ms, 500 ms, 650 ms, and 800 ms) were factorially crossed with age to investigate age-related differences in the buildup of semantic activation across time. The results from this task indicated that the activation pattern of the older adults closely mimicked that of the younger adults. Finally, the results of both tasks indicated that older adults were slower at both their onset to pronounce and their actual production durations (i.e., from onset to offset) in the pronunciation task. The results were interpreted as suggesting that input and output processes are slowed with age, but that the basic retrieval mechanism of spreading activation is spared by age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related alterations in muscular endurance

BACKGROUND: Steric strain in protein three-dimensional structures is related to unfavorable inter-atomic interactions. The steric strain may be a result of packing or functional requirements, or may indicate an error in the coordinates of a structure. Detailed energy functions are, however, usually considered too noisy for error detection. RESULTS: After a short energy refinement, a full-atom, detailed energy function becomes a sensitive indicator of errors. The statistics of the energy distribution of amino acid residues in high-resolution crystal structures, represented by models with idealized covalent geometry, were calculated. The interaction energy of each residue with the whole protein structure and with the solvent was considered. Normalized deviations of amino acid residue energies from their average values were used for detecting energy-strained and, therefore, potentially incorrect fragments of a polypeptide chain. Protein three-dimensional structures of different origin (X-ray crystallography, NMR spectroscopy, theoretical models and deliberately misfolded decoys) were compared. Examples of the applications to loop and homology modeling are provided. CONCLUSIONS: Elevated levels of energy strain may point at a problematic fragment in a protein three-dimensional structure of either experimental or theoretical origin. The approach may be useful in model building and refinement, modeling by homology, protein design, folding calculations, and protein structure analysis.     

Secondary cataracts in extreme myopia

INTRODUCTION: After cataract surgery there is a higher incidence of posterior capsular opacification (secondary cataract) in myopia than in normal population, and it varies from 40 to 60% [1, 2]. METHODS: Fifty myopic eyes operated for cataract at Prof. Dr. Ivan Stankovitsh Eye Department from 1988 to 1995 were examined for capsular opacification (secondary cataract). Extracapsular cataract extraction was performed in all patients and in 32 patients the posterior intraocular lens was placed. Capsular opacification was classified by type and treated with Nd:YAG laser or discussion at least 9 months to 3 years and 3 months from the operation. RESULTS: There were 13 secondary cataracts (26%) in our series of patients, of whom 22% with intraocular lenses, and 33% were aphakic patients. Visual acuity was 4/60 to 0.5. In 11 patients YAG-laser capsulotomy was performed and in one patient capsular discussion, and in one subject there was no treatment. Consequent visual acuity was 0.3 to 1.0. No correlation was found between the age, type of intraocular lens and capsular opacification. DISCUSSION: Capsular opacification is more often seen in myopic eyes and its treatment is associated with a higher rate of complications (cystoid macular oedema, rupture of anterior hyaloid, retinal detachment...) [3, 4]. It seems that posterior lens implants reduce the chance for development of posterior capsular opacification. The safest treatment is YAG-laser capsulotomy.     

Surgical correction of high myopia in phakic eyes with Worst-Fechner myopia intraocular lenses

BACKGROUND: Implanting an anterior chamber intraocular lens in a phakic eye is an effective surgical procedure for the correction of high myopia. However, the potential risks on the anterior segment structures are not well-known. We conducted a prospective study to evaluate the effectiveness, predictability, and safety after Worst-Fechner lenses were implanted to correct high myopia. METHODS: We studied 32 eyes with preoperative myopia from -9.50 to -27.00 diopters (D) (-16.60 +/- 6.29 D). All 32 eyes were studied by clinical specular microscopy, and the endothelium was analyzed for cell density. Twenty eyes were additionally examined by fluorophotometry for lens transmittance changes. Thirty eyes were additionally examined using the flare mode of a laser flare cell photometer for anterior chamber inflammation; the patients were divided into three subgroups of ten eyes each according to when the postoperative flare measurements were done: 12 months, 18 months, and 24 months. Thirteen phakic eyes with myopia greater than -6.00 D were used as a control group for the flare study. The mean follow-up was 18.3 +/- 8 months (range 6 to 24 mo). RESULTS: Fifty-seven per cent of eyes (16 of 28) had an uncorrected visual acuity of 20/40 or better 12 months after surgery, and 58% (10 of 17 eyes) at 24 months. Spectacle-corrected visual acuity improved: 0.15 at 12 months and 0.16 at 24 months (0.1 = one line) from preoperative values. Visual acuity was stable after 3 months. Eighty per cent of eyes (25 of 31) at 6 months, 75% (21 of 28) at 12 months, and 76.5% (13 of 17) at 24 months had been correctly planned to within +/-1.00 D of emmetropia. The refractive results were stable 3 months after surgery. The mean endothelial cell loss was 7.2% at 3 months, 10.6% at 6 months, 13% at 12 months, and 17.6% at 24 months after surgery. The mean lens transmittance loss was 0.62% at 3 months, 0.72% at 6 months, 0.82% at 12 months, and 1.03% at 18 months after surgery. Flare values were significantly higher for eyes implanted with Worst-Fechner lenses than were those of the control group in all periods under consideration (Mann-Whitney test, p < 0.05). A decentration greater than 0.5 mm was present in 43% of eyes (14 of 32), and halos in 56% (18 of 32). In three eyes (9.3%), fixation of the lens to the iris was not stable. CONCLUSIONS: Our results for the Worst-Fechner myopia lens confirm earlier findings on the effectiveness of the refractive results. However, our study showed a continual decrease in endothelial cell density, a decrease in lens transmittance, and a chronic subclinical inflammation after the implantation of these lenses. Moreover, decentration was common, and the fixation of the IOL to the iris was not stable in some eyes.     

Age-related macular degeneration

A general overview of age-related macular degeneration, including its definition, classification, and epidemiology, is followed by specifically described clinical findings of this disorder. Included are the differential diagnosis, histopathology, prevalence, risk factors, and natural history of each individual form. Also presented are the issues of optometric management, including clinical recognition of choroidal neovascularization, timely referral for retinal consultation and angiography, preventive therapies, current and emerging trends in the medical and surgical treatment, and appropriate follow-up.     

Combined method for treating false myopia and preventing axial myopia

None of the numerous methods for optic and drug treatment of the accommodation cramp effectively arrests it without long tiresome training or atropine, which limits visual working capacity for a long time and therefore, precludes starting the treatment on an outpatient basis immediately. Use of an available, simple, and effective combined method for treating the accommodation cramp helped prevent true myopia in 94.3% of young children in the main group, whereas 38.3% children in the control group developed myopia.     

Age-related macular degeneration

Age-related macular degeneration is the leading cause of non treatable blindness in industrialized countries. The impairment of visual acuity is preceded by the occurrence of "precursors" some of which are the witness of aging and others are the first symptoms of age-related degeneration of the macular retina. The disease involves both eyes with time resulting in a major handicap. Eventually, central visual acuity is destroyed, making reading, writing and recognition of faces impossible. Different clinical types are identified: the atrophic form for which there is at present no possibility of treatment, and the neovascular form in which the destruction of the new vessels with laser photocoagulation is beneficial. However, only an early diagnosis and treatment may allow a preservation of central vision. New possibilities of angiographic diagnosis, new therapeutic approaches (macular surgery or transplantation) based on physiopathogenic research, provide new hopes.     

Age-related macular degeneration

Clinical analysis of the blood is a most prevalent investigation in practical medicine. The need in effective assessment of the results of blood analysis prompted the creation of automated flow systems. Our task was to analyze the blood of normal subjects and patients by Hoffmann La Roche Cobas Micros-18 OT (France). It is a completely automated hematological analyzer used for in vitro diagnostic tests of whole blood. The work consisted of two steps: 1) comparison of the results of leukocyte and red cell counting by Cobas Micros and Goryayev chamber and 2) assessment of the leukocyte formula in blood donors and patients with diseases other than hematological by the Cobas Micros device and compare the results with the data of visual assessment in optic microscope. The results of analysis by the automated scintillator, Goryayev's chamber, and optic microscopy were compatible. Cobas Micros is very convenient for analysis of liquid blood on an outpatient and inpatient basis and during overall screenings. The device facilitates the deciphering of the leukocytic formula and assessment of the status of formed elements of the blood in mass screenings and detection of abnormalities.     

Age-related macular degeneration

Macular degeneration is now responsible for approximately 95% of blindness and partial sighted registrations in the UK. This review has been written specifically to make the general medical community of the UK aware of the prevalence and clinical manifestations of aged-related macular degeneration. The review encompasses the risk factors, the disabilities and problems experienced by suffers of the condition and current therapeutic options. Age related macular degeneration increases in prevalence in our community from 0% among people under 55 years old to 18.5% among those 85 years or older. There is a marked female preponderance. The exudative form of the disorder is commoner. Treatment remains supportive for most patients with macular degeneration although a minority will benefit from macular laser photocoagulation.     

Criterion shifts in recall.

Examined criterion shifts in recall in light of clarifications of the distinction between Type I and Type II signal detection analyses and of the concept of criterion. With a new index of the criterion, B. B. Murdock's evidence for criterion shifts in recall is found to be evidence that Ss hold their criteria constant across different retention intervals. However, with the new criterion index, criterion shifts are found in intelligibility experiments and in the short-term recall experiment by E. L. Bjork and A. F. Healy. In these studies, Ss' criteria became more lax with increasing task difficulty. A possible strategy used by the Ss is proposed to explain this finding as well as the finding that the Ss shift their criteria in Bjork and Healy's task but not in Murdock's. Finally, this analysis is applied to recall studies in which the S is allowed to leave blanks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related changes in odor discrimination.

Odor naming and recognition memory are poorer in children than in adults. This study explored whether such differences might result from poorer discriminative ability. Experiment 1 used an oddity test of discrimination with familiar odors on 6-year-olds, 11-year-olds, and adults. Six-year-olds were significantly poorer at discrimination relative to 11-year-olds and adults, who did not differ. Experiment 2 used the same procedure but with hard-to-name visual stimuli and compared only 6-year-olds with adults (as with the remaining experiments in this study). There was no difference in performance between these groups. Experiment 3 used the same procedure as Experiment 1 but with less familiar odors. Six-year-olds were significantly poorer at discrimination than adults. In Experiment 4 the researchers controlled for verbal labeling by using an articulatory suppression task, with the same basic procedure as in Experiment 1. Six-year-old performance was the same as for Experiment 1 and significantly poorer than that of adults. Impoverished olfactory discrimination may underpin performance deficits previously observed in children. These all may result from their lesser experience with odors, relative to adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related changes in the tip-of-the-tongue experience

The tip-of-the-tongue (TOT) experience was compared in younger and older adults, using picture and definition cues to elicit TOTs. Older adults (a) experienced more TOTs, (b) had less target word information available during the TOT, and (c) had more related words (blockers) come to mind during the TOT. There were no age differences in either the speed or likelihood of immediate resolution of the TOT. Picture and definition cues were equally likely to evoke TOTs, although picture cues elicited more interlopers. The idea that TOTs are more likely to be elicited by less common target words was not supported.     

Age-related differences in irrelevant-speech effects.

Three experiments examined age-related differences in irrelevant-speech effects. Younger and older adults were required to recall short prose texts or lists of semantically related words presented visually together with distractor speech. In all experiments, older adults made more semantically related intrusion errors from the irrelevant speech than younger adults. Results of a source memory test suggested that these age-related differences in interference are most likely due to both inhibitory deficits and source-monitoring problems. The results lend partial support to the inhibition deficit theory of cognitive aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)