Visualizing the Human Subcortex Using Ultra-high Field Magnetic Resonance Imaging.

With the recent increased availability of ultra-high field (UHF) magnetic resonance imaging (MRI), substantial progress has been made in visualizing the human brain, which can now be done in extraordinary detail. This review provides an extensive overview of the use of UHF MRI in visualizing the human subcortex for both healthy and patient populations. The high inter-subject variability in size and location of subcortical structures limits the usability of atlases in the midbrain. Fortunately, the combined results of this review indicate that a large number of subcortical areas can be visualized in individual space using UHF MRI. Current limitations and potential solutions of UHF MRI for visualizing the subcortex are also discussed.

Testing the factor structure of the Family Quality of Life Survey - 2006.

BACKGROUND: Although the Family Quality of Life Survey - 2006 (FQOLS-2006) is being used in research, there is little evidence to support its hypothesised domain structure. The purpose of this study was to test the domain structure of the survey using confirmatory factor analysis. METHOD: Samples from Australia, Canada, Nigeria and the USA were analysed using structural equation modelling. The data from Australia, Canada and the USA were combined on the assumption that these countries are similar, at least to some degree, in economic development, language and culture. The Nigerian data were analysed on its own. The analysis was undertaken in two phases. First, the hypothesis that each of nine domains of the FQOLS-2006 is a unidimensional construct that can reliably measure the dimensions Importance, Stability, Opportunities, Attainment, Stability and Satisfaction was tested. Second, the hypothesis that family quality of life (FQoL) is a single latent construct represented by the nine domains measured in the FQOLS-2006 was tested. RESULTS: In the first phase of the analysis, the Importance dimension was dropped because of skewness and lack of variance. The Stability dimension did not fit well within the individual domain model in both the Nigerian and the combined three countries' data. When Importance and Stability were excluded, the individual domain models showede good or acceptable fit when error variances of some dimensions were allowed to correlate. In the second phase of the analysis, the overall model, FQoL, represented by the nine domains of the FQOLS-2006 showed good fit in both data sets. CONCLUSIONS: The conceptual model of the FQOLS-2006 was supported with some qualifications. Each domain on the survey can be reliably measured by four dimensions Opportunities, Initiative, Attainment and Satisfaction. The dimensions of Importance and Stability, however, did not fit. Data reported on these dimensions from past and current studies should be interpreted with caution. The construct of FQoL is also reliably measured by the domains of the FQOLS-2006. Further research into the psychometric properties of the survey, particularly from a cross-cultural perspective, is needed.

Family quality of life among families with a member who has an intellectual disability: an exploratory examination of key domains and dimensions of the revised FQOL Survey.

BACKGROUND: The Family Quality of Life Survey (FQOLS-2006) was developed as the result of increased interest in family quality of life (FQOL) among families with a member who has an intellectual disability (ID). The instrument includes nine life domains and six dimensions reflecting the main areas and characteristics of FQOL. The aim of the current study was to provide a descriptive analysis of the domains and dimensions of the survey and to explore their relationship to one another and to global satisfaction. METHOD: A convenience sample of 35 participants with a family member who had ID completed the FQOLS-2006 in a large urban centre in Canada. The data were analysed using descriptive analyses. RESULTS: The findings showed that although participants differentiated between different domains and dimensions, as reflected in their variability, stability was also found. For example, support from others was rated lowest across most dimensions, while family relationships and health of the family were generally rated higher. CONCLUSIONS: The findings strengthen the importance of examining both the overall perception of FQOL as well as the perceptions in individual life domains. Moreover, they highlight the need to examine each life domain according to its various dimensions. In sum, the results call for further examination of the FQOLS-2006 as a useful tool for assessing FQOL and for implementing services based on it.

Education in psychogeriatrics: the leap of the imagination.

In an attempt to bridge the gap between healthy young people in their early 20s and mentally ill old people in their 80s six consecutive classes of final-year medical students of psychogeriatrics were asked to imagine and to record how they thought they might feel in certain fictitious situations which lay nearer to their own experience. They then explored links between the given situations and the feelings which might be experienced by mentally ill elderly people and their carers. The exercise has proved to be a popular and creative learning experience.

The effect of visual deprivation and proprioceptive change on postural sway in healthy adults.

In 39 healthy active people aged 17 to 79 who had not fallen, anteroposterior sway during quiet standing increased slightly with age; there was no increase with age in lateral sway. Sway increased on deprivation of visual information and altered proprioception due to foot pressure sensory change in all age groups, and especially when both forms of sensation were altered concurrently; but the increase of sway on pressure sensory change was no greater in the older than in the younger subjects.

Reversible unfolding of the gelatin-binding domain of fibronectin: structural stability in relation to function.

Fibronectin, a large multidomain glycoprotein, binds denatured collagen (gelatin) and mediates cell attachment and spreading on collagen-coated surfaces. Despite the high affinity, binding to gelatin is disrupted by relatively mild conditions. We have examined the effects of denaturants on the structure and function of a 42-kDa gelatin-binding fragment (GBF) isolated from chymotryptic and thermolytic digests of the parent protein. Application of linear gradients to GBF-loaded gelatin-agarose columns resulted in peak elution of the fragment at pH 5.2 or 10.2, at 0.4 M dimethylformamide, 0.9 M GdmCl, or 2.0 M urea, conditions far short of those required to induce structural changes detectable by fluorescence or circular dichroism. Solvent perturbation, fluorescence quenching, and chemical modification experiments indicate that about half of the 8 tryptophans, one-third of the 21 tyrosines, and all of the 9 lysine residues are solvent-exposed in the native protein and that 1 or more of the latter are directly involved in binding to gelatin, most likely through a hydrogen-bonding mechanism. Titration with GdmCl produced a single unfolding transition centered near 2.5 M GdmCl as monitored by changes in fluorescence and circular dichroism. This transition was fully reversible with complete recovery of structural parameters and gelatin binding. Treatment with disulfide reducing agents caused rapid irreversible changes in structure similar to those produced by GdmCl with concomitant loss of gelatin binding. Thus, tertiary and secondary structures are important for binding, but binding can be disrupted without perturbing those structures.

The efficiency and effectiveness of geriatric day hospitals.

One hundred patients who were referred consecutively to two geriatric day hospitals were followed for 3 months, to determine the efficiency and effectiveness of day hospital management. Transport was highly efficient; only one in every 40 attendances failed because of transport. Selection of patients may have been less efficient, in that only half completed planned treatment. In most cases this was because of progression of the illness. Time at the day hospital was on the whole efficiently used, in that three-quarters of the time was devoted to programmed activities. The effectiveness of the day hospital was limited. In only about one-third of referred patients were the objectives set by the doctor attained. Likewise only one-third of patients felt that they had improved, and one-third of carers experienced relief of strain.

Visual push: a sensitive measure of dynamic balance in man.

Forty-six subjects aged 17 to 79 years who had not fallen in the previous year were exposed to an illusory visual stimulus while they stood on a force platform, with or without the introduction of a polyurethane foam pad under their feet to reduce proprioception. The amplitude of sway obtained in this way was not correlated to age, but the sway path in the anteroposterior plane increased logarithmically with increase in age. The method proved to be more sensitive than similar measures obtained without the illusory visual stimulus.

Balance function in elderly people who have and who have not fallen.

Balance function was measured by a "visual push" method in three groups of subjects aged 65 and over. These groups were comprised of 27 "recent fallers" who had fractured their wrists, 15 subjects who had fallen at least once in the previous year although not recently ("remote fallers"), and 20 subjects who had not fallen in the previous year ("nonfallers"). Subjects who had fallen recently or remotely had significantly more sway on illusory visual stimulation than subjects who had not fallen. The "visual push" test of balance may be capable of distinguishing between elderly people who are and who are not at enhanced risk of falling.

Interaction of fibronectin and its gelatin-binding domains with fluorescent-labeled chains of type I collagen.

Fluorescent probes have been used to obtain dissociation constants for the fluid-phase interaction of human plasma fibronectin and several of its gelatin-binding fragments with purified alpha chains of type I rat tail collagen, as well as with a cyanogen bromide fragment (CB7) of the alpha 1 chain in 0.02 M Tris buffer containing 0.15 M NaCl at pH 7.4. Addition of fibronectin to fluorescein-labeled collagen chains caused a dose-dependent increase in the fluorescence anisotropy which continued over several logs of titrant concentration. Scatchard-type plots of the anisotropy response were biphasic indicating the presence of one or more weak sites (Kd greater than microM) along the collagen chain in addition to a strong site characterized by Kd = 1.3 X 10(-8) M at 25 degrees C. Gelatin-binding fragments with Mr = 42,000, 60,000, and 72,000 also produced a biphasic response with Kd values for the high affinity site being 10- to 20-fold greater than for intact fibronectin. Binding of fibronectin and its fragments to fluorescent-labeled CB7 was essentially the same as to the whole alpha 1 chain. In all cases, the anisotropy response could be reversed or prevented by addition of excess unlabeled gelatin or CB7, but not by synthetic peptides spanning the collagenase cleavage site of alpha 1 (I). Studies of the temperature dependence of Kd for binding of fibronectin to the high affinity site on alpha 1 produced a value of +16 kcal/mol for the enthalpy of dissociation below 30 degrees C. Above this temperature, fibronectin appeared to undergo a subtle conformational transition characterization by a reduced affinity for collagen. This transition occurred in whole fibronectin but not in the gelatin-binding fragments and may involve disruption of intramolecular interactions between different domains.

Why do old people stoop?

Measurements of balance and of stooping were made in 38 healthy and active volunteers of various ages, and in 16 patients who had suffered falls and subsequent limitations of mobility. All subjects were able to stand unsupported for 30 seconds. Balance function as measured sensitively on a Kistler force plate showed a tendency to progressive impairment with increasing age. No difference was detected in balance between those who had fallen and between normal subjects of the same age. No relationship was observed between the measurements of stooping and age or the occurrence of a fall. Stooping does not occur as an adaptation to the minor degrees of balance impairment demonstrated in these subjects.

Interaction of blood coagulation factor Va with phospholipid vesicles examined by using lipophilic photoreagents.

Two different lipophilic photoreagents, [3H]adamantane diazirine and 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine (TID), have been utilized to examine the interactions of blood coagulation factor Va with calcium, prothrombin, factor Xa, and, in particular, phospholipid vesicles. With each of these structurally dissimilar reagents, the extent of photolabeling of factor Va was greater when the protein was bound to a membrane surface than when it was free in solution. Specifically, the covalent photoreaction with Vl, the smaller subunit of factor Va, was 2-fold higher in the presence of phosphatidylcholine/phosphatidylserine (PC/PS, 3:1) vesicles, to which factor Va binds, than in the presence of 100% PC vesicles, to which the protein does not bind. However, the magnitude of the PC/PS-dependent photolabeling was much less than has been observed previously with integral membrane proteins. It therefore appears that the binding of factor Va to the membrane surface exposes Vl to the lipid core of the bilayer, but that only a small portion of the Vl polypeptide is exposed to, or embedded in, the bilayer core. Addition of either prothrombin or active-site-blocked factor Xa to PC/PS-bound factor Va had little effect on the photolabeling of Vl with TID, but reduced substantially the covalent labeling of Vh, the larger subunit of factor Va. This indicates that prothrombin and factor Xa each cover nonpolar surfaces on Vh when the macromolecules associate on the PC/PS surface. It therefore seems likely that the formation of the prothrombinase complex involves a direct interaction between Vh and factor Xa and between Vh and prothrombin.(ABSTRACT TRUNCATED AT 250 WORDS)

Nursing the immobile: a preliminary study.

Permanent loss of mobility has profound physical and mental consequences for both sufferers and carers, and is a major challenge to the National Health Service. A recent study has shown that 42% of beds in departments of Geriatric Medicine are occupied by people with longstanding immobility. These people are highly dependent on nursing staff for their daily activities and quality of life. The assessment of mobility, as a single parameter of dependency, and the measurement of allocated nursing hours are both rapidly and easily performed on geriatric wards. It is felt that a simple correlation of these two variables might highlight areas where more detailed audit is desirable. This study demonstrates that the more immobile patients on a ward, the less the hours allocated to Registered and Learner grade nurses. Some possible reasons for this are suggested and the effects of this deployment on nursing practice and staff recruitment are discussed. It is felt that provision of appropriate nursing care to the most dependent patients in continuing care areas is essential, and that high levels of trained staff are needed to ensure this.

Persistence of a mycotic aneurysm of the intracavernous carotid artery.

Mycotic aneurysms of the intracavernous portion of the carotid artery are rare, especially in children. In reported cases, treatment has been by antibiotics alone, or by some form of carotid surgery. In the present case only antibiotic therapy was used. Subsequent angiography showed spontaneous thrombosis of the internal carotid artery, but persistence of the mycotic aneurysm. The implications of these findings are discussed with regard to the management of the condition.

A domain of membrane-bound blood coagulation factor Va is located far from the phospholipid surface. A fluorescence energy transfer measurement.

The larger subunit of blood coagulation factor Va was covalently labeled with iodoacetamido derivatives of fluorescein and rhodamine without loss of functional activity, as measured by either the one-stage clotting assay or the ability to accelerate prothrombin activation in a purified system. The spectral properties of the dyes were not altered by the presence or absence of the smaller subunit of factor Va, Ca2+, prothrombin, factor Xa, or phosphatidylcholine/phosphatidylserine (PC/PS, 4:1) vesicles. When fluorescein-labeled protein (factor VaF) was titrated with PC/PS vesicles containing either octadecylrhodamine or 5-(N-hexadecanoylamino)eosin, fluorescence energy transfer was observed between the protein-bound donor dyes and the acceptor dyes at the outer surface of the phospholipid bilayer. The extent of energy transfer correlated directly with the extent of protein binding to the vesicles monitored by light scattering. The distance of closest approach between the fluorescein on factor Va and the bilayer surface averaged 90 A for the two different acceptors. Association of factor VaF with factor Xa on the phospholipid surface reduced this separation by 7 A, but association with prothrombin did not alter the distance between the labeled domain on factor VaF and the surface. The efficiency of diffusion-enhanced energy transfer between rhodamine-labeled factor Va and terbium dipicolinate entrapped inside PC/PS vesicles was less than 0.01, consistent with the location of the dye far above the inner surface of the vesicle. Thus, a domain of membrane-bound factor Va is located a minimum of 90 A above the phospholipid surface.(ABSTRACT TRUNCATED AT 250 WORDS)

Balance in elderly patients: the "get-up and go" test.

The "get-up and go test" requires patients to stand up from a chair, walk a short distance, turn around, return, and sit down again. This test was conducted in 40 elderly patients with a range of balance function. Tests were recorded on video tapes, which were viewed by groups of observers from different medical backgrounds. Balance function was scored on a five-point scale. The same patients underwent laboratory tests of gait and balance. There was agreement among observers on the subjective scoring of the clinical test, and good correlation with laboratory tests. The get-up and go test proved to be a satisfactory clinical measure of balance in elderly people.