Progressive Age-Related Changes Similar to Age-Related Macular Degeneration in a Transgenic Mouse Model

Age-related macular degeneration (AMD) is the major cause of blindness in the developed world. its pathomechanism is unknown and its late onset, complex genetics and strong environmental components have all hampered investigations. Here we demonstrate the development of an animal model for AMD that reproduces features associated with geographic atrophy, a transgenic mouse line (mcd/mcd) expressing a mutated form of cathepsin D that is enzymatically inactive thus impairing processing of phagocytosed photoreceptor outer segments in the retinal pigment epithelial (RPE) cells. Pigmentary changes indicating RPE cell atrophy and a decreased response to flash electroretinograms were observed in 11- to 12-month-old mcd/mcd mice. Histological studies showed RPE cell proliferation, photoreceptor degeneration, shortening of photoreceptor outer segments, and accumulation of immunoreactive photoreceptor breakdown products in the RPE cells. An accelerated photoreceptor cell death was detected in 12-month-old mcd/mcd mice. Transmission electron microscopy demonstrated presence of basal laminar and linear deposits that are considered to be the hallmarks of AMD. Small hard drusen associated with human age-related maculopathy were absent in the mcd/mcd mouse model at the ages analyzed. in summary, this model presents several features of AMD, thus providing a valuable tool for investigating the underlying biological processes and pathomechanism of AMD.

Immunoglobulins in saliva of preterm and full-term infants. A longitudinal study from 0-18 months of age

The aim of this longitudinal study was to determine salivary levels of total IgA, IgG and IgM in 84 preterm and 214 full-term infants, from birth to 18 months of age. Unstimulated whole saliva was collected from each infant at birth, and subsequently at 3-monthly intervals. Immunoglobulin levels were estimated using an ELISA technique. At birth, IgA was detected in 147/214 (69%) full-term infants but only 47/84 (56%) preterm infants (P

America's nuclear deterrence in the age of terrorism

The September 11, 2001 terrorist attacks in the US and the leakage of the Nuclear Posture Report (NPR) spur a complete review of the nuclear doctrine under Pres George W. Bush's administration. Kampmark discusses the contrariness of NPR in relation to America's deterrence of nuclear weapons and the possible proliferation of tactical offensive weapons as compared to strategic nuclear weapons.

Invertebrate D2 type dopamine receptor exhibits age-based plasticity of expression in the mushroom bodies of the honeybee brain

We have isolated a cDNA clone from the honeybee brain encoding a dopamine receptor, AmDop2, which is positively coupled to adenylyl cyclase. The transmembrane domains of this receptor are 88% identical to the orthologous Drosophila D2 dopamine receptor, DmDop2, though phylogenetic analysis and sequence homology both indicate that invertebrate and vertebrate D2 receptors are quite distinct. In situ hybridization to mRNA in whole-mount preparations of honeybee brains reveals gene expression in the mushroom bodies, a primary site of associative learning. Furthermore, two anatomically distinct cell types in the mushroom bodies exhibit differential regulation of AmDop2 expression. In all nonreproductive females (worker caste) and reproductive males (drones) the receptor gene is strongly and constitutively expressed in all mushroom body interneurons with small cell bodies. In contrast, the large cell-bodied interneurons exhibit dramatic plasticity of AmDop2 gene expression. In newly emerged worker bees (cell-cleaning specialists) and newly emerged drones, no AmDop2 transcript is observed in the large interneurons whereas this transcript is abundant in these cells in the oldest worker bees (resource foragers) and older drones. Differentiation of the mushroom body interneurons into two distinct classes (i.e., plastic or nonplastic with respect to AmDop2 gene expression) indicates that this receptor contributes to the differential regulation of distinct neural circuits. Moreover, the plasticity of expression observed in the large cells implicates this receptor in the behavioral maturation of the bee.

Abnormal left ventricular filling with increasing age reflects abnormal myocardial characteristics independent of ischemia or hypertrophy

Abnormal left ventricular (IV) filling may occur with increasing age despite apparently normal IV size and function, and is usually attributed to IV hypertrophy and coronary artery disease. The purpose of this study was to determine whether myocardial abnormalities could be identified in 67 such patients (36 men, mean age 57 +/- 9 years) whose IV hypertrophy and coronary artery disease were excluded by dobutamine echocardiography. All patients underwent gray scale and color tissue Doppler imaging from 3 apical views, which were stored and analyzed off line. Disturbances in structure and function were assessed by averaging the cyclic variation of integrated backscatter, strain rate, and peak systolic strain from each myocardial segment. Calibrated integrated backscatter (corrected for pericardial backscatter intensity) was measured in the septum and posterior wall from the parasternal long-axis view. Abnormal IV filling was present in 36 subjects (54%). Subjects with and without abnormal IV filling had similar IV mass, but differed in age (p <0.01), cyclic variation (p = 0.001), strain rate (p <0.01), and peak systolic strain (p <0.001). Multivariate logistic regression analysis demonstrated that age (p = 0.016) and cyclic variation (p = 0.042) were the most important determinants of abnormal IV filling in these apparently normal subjects. (C) 2003 by Excerpta Medica, Inc.

Contradiction between the average age of retirement at the time of death and the average pension time for men and women in public employment in Portugal

The short article attempts to make some very brief reflections on the effects a lack of public policies positively discriminatory in terms of public employment retirement. In particular, the observation of the absurd contradiction between the average age of retirement at the time of death (for men and women) and the average pension time for men and women in public employment in Portugal.

Effects of Age-Related Cognitive Deficits on EEG Phase Coherence

Body and brain undergo several changes with aging. One of these changes is the loss of neuroplasticity, which leads to the decrease of cognitive abilities. Hence the necessity of stopping or reversing these changes is of utmost importance to contemporary society. In the present work, electroencephalogram (EEG) markers of cognitive decline are sought whilst the subjects perform the Wisconsin Card Sorting Test (WCST). Considering the expected age-related cognitive deficits, WCST was applied to young and elder participants. The results suggest that coherence on theta and alpha EEG rhythms decrease with aging and increase with performance. Additionally, theta phase coherence seems more sensitive to performance, while alpha synchronization appears as a potential ageing marker.

Cognitive intervention protocol for age-related memory impairments

With the number of elderly people increasing tremendously worldwide, comes the need for effective methods to maintain or improve older adults' cognitive performance. Using continuous neurofeedback, through the use of EEG techniques, people can learn how to train and alter their brain electrical activity. A software platform that puts together the proposed rehabilitation methodology has been developed: a digital game protocol that supports neurofeedback training of alpha and theta rhythms, by reading the EEG activity and presenting it back to the subject, interleaved with neurocognitive tasks such as n-Back and Corsi Block-Tapping. This tool will be used as a potential rehabilitative platform for age-related memory impairments.

Corporal and testicular biometry in wild boar from birth to 12 months of age

The aim of this tudy was to evaluate corporal and testicular development in wild boars (Sus scrofa scrofa) from birth to 12 months of age, evaluating body weight, biometric testicular parameters, and gonadosomatic index. Thirty-nine male wild boars from a commercial farm licensed by IBAMA were used in the study. The animals were weighed and assigned to 13 experimental groups. The testes were recovered through unilateral orchiectomy, weighed on an analytical balance and measured for length, width and thickness. Body weight and testicular measures increased with the age, up to 12 months, and were more accelerated in the first and ninth months. Initially the testicular growth pattern, between zero and nine months, followed the body growth, and the gonadosomatic index varied from 0.07 to 0.09%. Between 9 and 11 months, the testicular growth was superior to the body growth, and the gonadosomatic index varied from 0.09 to 0.16%. Finally, after 11 months of age, testicular and body growth had a similar behavior. In conclusion, body weight, testicular biometry, and gonadosomatic index development accelerated in the ninth month.

Loneliness in Middle and Old Age

Purpose of the research: (a) To identify the degree of much loneliness reported in the Portuguese population over 50 years of age and (b) test whether loneliness can be predicted by socio-demographic, health related or social characteristic of the sample other than age. Materials and methods: 1174 late middle age and older adults were interviewed face to face by different interviewers across the country; after the informed consent was signed, we asked the participants several socio-demographic and health-related questions; finally we asked ‘‘How often do you feel lonely?’’ and participants responded according to a five point Likert scale. Principal results: The results showed that 12% of participants reporting feeling lonely often or always, whereas 40% reporting never feeling lonely. The remaining 48% self-reported they felt lonely seldom or sometimes. Additionally, results show that, when taken together, variables such as marital status, type of housing, residence settings, health conditions, social satisfaction, social isolation, lack of interest, transportation, and age were predictors of loneliness. Major conclusions: (1) The association of loneliness with advanced age has been greatly exaggerated by mass media and common sense; (2) But although our findings did not confirm the most alarmist views, the 12% of older adults reporting that they are feeling lonely always or often should be cause for attention and concern. It is necessary to understand the meaning, reasons and level of suffering implied on those feelings of loneliness. (3) Our findings suggest that it makes no sense to construe age as a singular feature or cause for feelings of loneliness. Instead, age and also a number of other features combine to predict feelings of loneliness. But even with our predictor variables there was a substantial of variance left unexplained. Therefore it is necessary to continue exploring how feelings of loneliness arise from the experience of living and how they can be changed.

The impact of size and age of the company on assessing financial risk

Textiles and tourism sectors are two important sectors in Portuguese economy. Its high exposure to both internal and international economy volatility transform the companies operating in these economic sectors especially vulnerable to recent economic crises in Portugal and European Union. The objective of this paper is to evaluate and understand the impact of size and age on the financial health of textile and tourism companies, measured by economic indices. An empirical based model is proposed. Its implications are derived and tested on a sample of 4061 Portuguese companies from textile and tourism sector, during the period 2005-2009. The results conclude that age has a stronger impact on the risk of failure than size. Whereas the effect of age is generally positive regarding the financial health of the company, the effect of size is less clear and depends on the age of the company.

Effects of age on histological parameters of the sweat glands of Nellore cattle

The sweat glands are important in thermoregulation of cattle in a warm environment as they help dissipate heat through evaporation. Studies on gland histology are important to define its secretion potential and the capacity of perspiration and heat removal. The objective of this study was to determine, by histomorphometry, glandular epithelium height, the depth of the gland, length of the glandular portion and number of glands per cm2 of the sweat glands of the three age groups of Nellore cattle. Thirty females were used in this study. They were equally divided into calves, heifers and cows. Histological sections were obtained and analyzed by digital images in Trinocular BX40 Olympus microscope coupled to an Oly - 200 camera, connected to a computer. The images were obtained with microscope with 2x, 4x, 10x and 40x magnification objectives. The measurements were performed using HL Image 97 program. The height of glandular epithelium, depth of the glands, length and density of the glandular portion per cm2 , were all analyzed. The calves showed greater height of the glandular epithelium than heifers (P = 0.0024), and cows (P = 0.0191). The depth of the gland was not influenced by age. Cows had higher length of secretory portion than heifers (P = 0.0379) and calves (P = 0.0077). Heifers had a greater number of sweat glands per cm2 of skin than cows (P = 0.023). In cattle, the height of glandular epithelium and the density decreases as animals get older. On the other hand, the length of the secretor portion increases but with no changes in the depth of the sweat glands