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Asymmetry in optic disc morphometry as measured by heidelberg retina tomography in a normal elderly population: the Bridlington Eye Assessment Project.

PURPOSE: To define the normal range of asymmetry in optic disc parameters measured by the Heidelberg Retina Tomograph (HRT II; Heidelberg Engineering GmbH, Dossenheim, Germany) in a normal elderly population. METHODS: Optic disc analysis of 918 eyes of 459 normal elderly patients was performed. All patients were consecutive in a cohort screened for eye disease. Normality was defined with a normal visual field on automated suprathreshold screening, intraocular pressure less than 22 mm Hg, and minimum corrected visual acuity of 6/12. Asymmetry measures were calculated by subtracting the values of the smaller disc from those of the larger disc. RESULTS: Subjects' mean age (262 female and 197 male) was 72.6 years (range, 65.5-89.3). There was no significant difference in disc area or rim area between the right and left eyes. Neither rim-to-disc area ratio asymmetry nor rim measurement asymmetries were significantly affected by age or sex. Rim-to-disc area ratio asymmetry was much less affected by the increasing difference in disc size than was absolute rim asymmetry. The 2.5th and 97.5th percentile limits of normality for the rim-to-disc area ratio asymmetry in the global and temporal-inferior analyses were -0.212 and 0.154, and -0.331 and 0.261, respectively. CONCLUSIONS: The normal range of parameter asymmetry in an age group relevant to glaucoma may be useful in the discrimination of normal from early glaucoma. Asymmetry analysis may improve discriminatory ability by reducing parameter variability based on disc size. The rim-to-disc area ratio asymmetry measure is likely to be the most useful parameter in describing normality with consistency.

Aged↗

Separate populations of primary sensory neurons project to the splanchnic nerve and thoracic spinal nerve rami of the rat. A fluorescent double labelling study.

Using fluorescent double labelling technique with one tracer applied to the greater splanchnic nerve and a second to the ventral or dorsal spinal nerve ramus at the T9 level, it was shown that two separate populations of sensory nerve cell bodies in the T9 dorsal root ganglion were projecting to the splanchnic nerve and spinal rami, respectively. Only two double labelled cells were detected. The results support the theory that spinal and/or supraspinal interactions and not dichotomizing sensory axons are responsible for referred pain.

Animals↗

[Modeling and projecting mortality in Chile].

"In a recent paper, Lee and Carter developed a new method for analyzing and forecasting time series of age specific mortality, and applied it to the U.S. population. In this paper, we extend that method to deal with various problems of incomplete data common in Third World populations, and then apply the method to forecast mortality in Chile." (SUMMARY IN ENG)

Americas↗

Connections of a motor cortical region in zebra finches: relation to pathways for vocal learning.

The lateral magnocellular nucleus of the anterior neostriatum (lMAN) is necessary for both initial learning of vocal patterns in developing zebra finches, as well as for modification of adult song under some circumstances. Lateral MAN is composed of two subregions: a core of magnocellular neurons and a surrounding shell composed primarily of parvocellular neurons. Neurons in lMAN(core) project to a region of motor cortex known as robust nucleus of the archistriatum (RA), whereas neurons in lMAN(shell) project to a region adjacent to RA known as dorsal archistriatum (Ad). We studied the axonal connections of Ad in adult male zebra finches. In contrast to RA, Ad neurons make a large number of efferent projections, which do not include direct inputs to vocal or respiratory motor neurons. The major efferent projections of Ad are to: (1) the striatum of avian basal ganglia; (2) a dorsal thalamic zone (including the song-control nuclei dorsomedial nucleus of the posterior thalamus [DMP] and dorsolateral nucleus of the medial thalamus [DLM]); (3) restricted regions within the lateral hypothalamus (stratum cellulare externum [SCE]), which may also relay information to the same dorsal thalamic zone; (4) a nucleus in the caudal thalamus (medial spiriform nucleus [SpM]); (5) deep layers of the tectum, which project to the thalamic song-control nucleus Uva; (6) broad regions of pontine and midbrain reticular formation; and (7) areas within the ventral tegmental area and substantia nigra (ventral tegmental area [AVT], substantia nigra [SN]), which overlap with regions that project to Area X, a song-control nucleus of avian striatum. Inputs to Ad derive not only from lMAN(shell), but also from a large area of dorsolateral caudal neostriatum (dNCL), which also receives input from lMAN(shell). That is, lMAN(shell) neurons project directly to Ad, and also multisynaptically to Ad via dNCL. Double-labeling studies show that lMAN(shell) contains two different populations of projection neurons: one that projects to Ad and another to dNCL. These results are exciting for two main reasons. The first is that some of these projections represent potential closed-loop circuits that could relay information back to song-control nuclei of the telencephalon, possibly allowing diverse types of song-related information to be both integrated between loops and compared during the period of auditory-motor integration. Because both auditory experience with an adult (tutor) song pattern and auditory feedback are essential to vocal learning, closed-loop pathways could serve as comparator circuits in which efferent commands, auditory feedback, and the memory of the tutor song are compared in an iterative fashion to achieve a gradual refinement of vocal production until it matches the tutor song. In addition, these circuits seem to have a strong integrative and limbic flavor. That is, the axonal connections of Ad neurons clearly include regions that receive inputs not only from somatosensory, visual, and auditory areas of cortex, but also from limbic regions, suggesting that they may be involved in higher order sensory processing, arousal, and motivation.

Animals↗

Utility of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) for dementia in a Japanese-American population.

Ethnic diversity among older patients in Hawai'i is common; yet few data exist concerning the applicability of cognitive testing instruments in non-Caucasian populations. This project aimed to determine the specificity and sensitivity of the IQCODE for the detection of cognitive impairment in a Japanese-American population. Results confirm that the IQCODE is a valuable tool for primary care physicians to detect impairment in this population.

Aged↗

Characterization of the extent of pontomesencephalic cholinergic neurons' projections to the thalamus: comparison with projections to midbrain dopaminergic groups.

We sought to determine whether pontomesencephalic cholinergic neurons which we have been shown previously to project to the substantia nigra and ventral tegmental area also contribute to the thalamic activation projection from the pedunculopontine and laterodorsal tegmental nuclei. Retrograde tracing, immunohistochemical localization of choline acetyltransferase and statistical methods were used to determine the full extent of the cholinergic projection from the pedunculopontine and laterodorsal tegmental nuclei to the thalamus. Progressively larger Fluoro-Gold injections in to the thalamus proportionally labeled increasing numbers of pontomesencephalic cholinergic cells both ipsi- and contralaterally in the pedunculopontine and laterodorsal tegmental nuclei. Multiple large thalamic injections left only a small fraction of the ipsilateral pontomesencephalic cholinergic group unlabeled. This small remainder did not correspond to the populations which project to the substantia nigra and ventral tegmental area, thereby indicating that substantia nigra- and ventral tegmental area-projecting cholinergic neurons must also project to the thalamus. We examined whether there existed any set of cholinergic neurons in the pedunculopontine and laterodorsal tegmental nuclei which did not innervate a thalamic target. The distribution of descending projections of the pedunculopontine and laterodorsal tegmental nuclei demonstrated that the unlabeled remainder cannot correspond to a purely descending group. We also show that substance P-positive cholinergic cells in the laterodorsal tegmental nucleus project to the thalamus. Further studies demonstrated that the small population of cholinergic cells left unlabeled from the thalamus were the smallest sized cholinergic cells, and included two groups of small, light-staining cholinergic cells located in the parabrachial area and central gray, adjacent to the main pedunculopontine and laterodorsal tegmental nuclei cholinergic groups. These small cells, in contrast to thalamic-projecting cholinergic cells, did not stain positively for reduced nicotinamide adenine dinucleotide phosphate-diaphorase. Taken together, these results indicated that all of the reduced nicotinamide adenine dinucleotide phosphate diaphorase-positive/choline acetyltransferase-positive neurons of the pedunculopontine/laterodorsal tegmental nuclei ascend to innervate some portion of the thalamus, in addition to the other targets they innervate. These findings indicate that the diverse physiological and behavioral effects attributed to the activity of pontomesencephalic cholinergic neurons should not be dissociated from their activating effects in the thalamus.

Animals↗

Life expectancy at age 60--epidemiologic scenarios assuming delayed mortality for selected causes of death.

"The present analysis offers a projection of life expectancy at advanced ages in Austria for the year 2010. To estimate the gains in life expectancy the Simultaneous Multiple Cause-Delay (SIMCAD) method is used. This model takes into account the epidemiological concept of an additional delay in the onset of particular chronic-degenerative diseases. While the results of the SIMCAD method vary only slightly on the whole from the official projection of life expectancy at age 60, the similarity between the two projections decreases steadily with increasing age. The SIMCAD model predicts higher gains in life expectancy for the oldest age-groups of the population than do the official statistics." (SUMMARY IN FRE)

Adult↗

Perioperative nursing challenges for the Russian emigré nurse.

Three San Francisco organizations participated in an integration program that focused on the design, implementation, and evaluation of a unique training project that prepared Russian émigré nurses for employment in the US health care industry. The Russian Nurse Project is a unique program that affiliates émigré nurses with specific language and cultural skills and focuses on the increasing Russian immigrant patient population. The project's implementation and diversity strategies, as they pertain to the perioperative areas of nursing practice in this country, are described.

Communication Barriers↗

The effects of atmospheric nitrogen deposition in the Rocky Mountains of Colorado and southern Wyoming, USA-a critical review.

The Rocky Mountains of Colorado and southern Wyoming receive atmospheric nitrogen (N) deposition that ranges from 2 to 7 kg ha(-1) yr(-1), and some previous research indicates pronounced ecosystem effects at the highest rates of deposition. This paper provides a critical review of previously published studies on the effects of atmospheric N deposition in the region. Plant community changes have been demonstrated through N fertilization studies, however, N limitation is still widely reported in alpine tundra and subalpine forests of the Front Range, and sensitivity to changes in snow cover alone indicate the importance of climate sensitivity in these ecosystems. Retention of N in atmospheric wet deposition is <50% in some watersheds east of the Continental Divide, which reflects low biomass and a short growing season relative to the timing and N load in deposition. Regional upward temporal trends in surface water NO(3)(-) concentrations have not been demonstrated, and future trend analyses must consider the role of climate as well as N deposition. Relatively high rates of atmospheric N deposition east of the Divide may have altered nutrient limitation of phytoplankton, species composition of diatoms, and amphibian populations, but most of these effects have been inconclusive to date, and additional studies are needed to confirm hypothesized cause and effect relations. Projected future population growth and energy use in Colorado and the west increase the likelihood that the subtle effects of atmospheric N deposition now evident in the Front Range will become more pronounced and widespread in the future.

Air Pollutants↗

Results of a quit-smoking research project in a randomly selected population.

In the spring of 1973, 58 strictly randomized heavy smokers from a defined population of men born in 1914 were asked to quit smoking, at least for 8-9 weeks, as a part of a research project focused upon the relationship between smoking and peripheral blood flow, fibrinolysis, and lung function. Eighty-eight per cent of the smokers were willing to try to quit smoking. Seven (12%) refused at the outset, as they regarded quitting as impossible. Of the remaining 51 it was possible to keep 31 (60%) free from smoking for 8-9 weeks with the aid of an intense anti-smoking program lasting 6 weeks. Checks of continued smoking abstention were made by questionnaire and COHb-determination. After six weeks, no further information was given to the subjects. A follow-up after 8-9 months revealed that 33% of the 51 participants (i.e. 29% of the original 58) were still non-smokers. The long-lasting effect of our quit-smoking method was equal to the best reported by others and 30% is probably the highest rate of long-term success to be achieved in smoking cessation.

Blood Circulation↗

Remarkable success in out-migration from poor areas.

The biggest migration since the founding of the People's Republic in 1949, has been quietly going on in West China. So far, 320,000 people have moved to the areas along the Yellow River, the Hexi Corridor (in Gansu Province), and the Hetao Area (at the top of the Great Bend of the Yellow River in the Ningxia Hui Autonomous Region) from the poor mountain areas of Gansu and southern Ningxia. About 130,000 more migrants will move out in the coming 2 years, thus raising the total number to 450,000. These figures were released by the Leading Group of Economic Development in Poor Areas under the State Council in mid-June 1991 at the Working Conference on Population Migration convened by Gansu and Ningxia. By unremitting effort over the past 8 years, there has been great success in this giant project of population redistribution. By the end of 1990, 50,000 people had moved from the dry mountain areas of Central Gansu to the Hexi Corridor and 160,000 to the newly developed irrigated areas along the Yellow River. 110,000 people outmigrated from the dry mountain areas of Xiji, Haiyuan, and Guyuan counties in southern Ningxia to the Hetao Area. In the past, these people had insufficient food and clothing, but after moving into irrigated areas they displayed a spirit of self-reliance in building their new lives. The settled migrants produced 405 kilograms of grain per capita yearly on the average, higher than the national average of 380 kilos of grain, thereby providing for most of their food and clothing after their settlement.

Agriculture↗