Prognosis of functional recovery 1 year after hip fracture: typical patient profiles through cluster analysis.

BACKGROUND: Many investigators have identified distinct medical, demographic and psychosocial prefracture conditions that influence the functional outcome of patients surgically treated for a fracture of the hip. However, to design efficient intervention care programs addressing the needs of these patients, at optimal economic and social costs, more information is required on the typical combinations of prognostic determinants actually encountered. METHODS: Data on specific descriptors of the prefracture status and on mobility and functioning 1 year after surgical intervention were collected by interview from 253 consecutive patients hospitalized for a fracture of the proximal femur. Cluster analysis was used to form homogeneous groups of patients with similar profiles in terms of the 13 predictive variables and the 7 outcome variables significantly interrelated. The modeling procedure generated four clusters of patients with a typical profile sharply contrasted by their structure. RESULTS: Subjects of two clusters could walk without difficulty and were functionally independent prior to their hip fracture. One year later, however, mobility and functioning were only fully recovered by the members of one cluster. The majority of predictors were of less favorable prognostic value for the members of the second cluster. The other two clusters regrouped patients with impaired prefracture mobility that were either unaltered or even aggravated 1 year later. CONCLUSIONS. Cluster analysis identified typical profiles of elderly hip fracture patients. Close scrutiny of their respective global structure, in terms of combined prognostic determinants and outcomes, may help to develop specific management strategies that are more efficiently adapted to these different groups of patients.

Semiconductor nanocrystals as fluorescent biological labels.

Semiconductor nanocrystals were prepared for use as fluorescent probes in biological staining and diagnostics. Compared with conventional fluorophores, the nanocrystals have a narrow, tunable, symmetric emission spectrum and are photochemically stable. The advantages of the broad, continuous excitation spectrum were demonstrated in a dual-emission, single-excitation labeling experiment on mouse fibroblasts. These nanocrystal probes are thus complementary and in some cases may be superior to existing fluorophores.

Organization of 'nanocrystal molecules' using DNA.

Patterning matter on the nanometre scale is an important objective of current materials chemistry and physics. It is driven by both the need to further miniaturize electronic components and the fact that at the nanometre scale, materials properties are strongly size-dependent and thus can be tuned sensitively. In nanoscale crystals, quantum size effects and the large number of surface atoms influence the, chemical, electronic, magnetic and optical behaviour. 'Top-down' (for example, lithographic) methods for nanoscale manipulation reach only to the upper end of the nanometre regime; but whereas 'bottom-up' wet chemical techniques allow for the preparation of mono-disperse, defect-free crystallites just 1-10 nm in size, ways to control the structure of nanocrystal assemblies are scarce. Here we describe a strategy for the synthesis of 'nanocrystal molecules', in which discrete numbers of gold nanocrystals are organized into spatially defined structures based on Watson-Crick base-pairing interactions. We attach single-stranded DNA oligonucleotides of defined length and sequence to individual nanocrystals, and these assemble into dimers and trimers on addition of a complementary single-stranded DNA template. We anticipate that this approach should allow the construction of more complex two- and three-dimensional assemblies.

Facial thermography during nasal provocation tests with histamine and allergen.

Changes of skin temperature (T degree) of the nose area during nasal provocation tests with histamine and allergen were followed by means of an infrared thermography camera. By a colimator system in which temperatures measured on a given surface can be integrated and averaged, thermography allows the continuous and quantitative recording of the temperature during the whole procedure in a completely noninvasive way. In 10 normal subjects, increasing doses of histamine induced a dose-dependent rise of the nose external temperature. No significant change was observed with the vehicle solution. In six subjects allergic to grass pollen, the nebulization of increasing concentrations of a pollen extract induced a dose-dependent rise in T degree. The T degree rise observed after histamine or allergen corresponded to a marked nasal obstruction. The nebulization of the highest dose of the pollen extract did not induce any T degree rise in six nonallergic subjects. The continuous recording of the skin temperature by a noninvasive method might yield additional information on the vascular changes rapidly occurring during nasal challenges.

[Cardiovascular polymorbidity as a function of psycho-organic status. A series of 904 pathological and neuropathological comparisons]. / Polymorbidité cardiovasculaire en fonction de l'état psycho-organique. Série de 904 confrontations pathologiques et neuropathologiques.

In the past decades, the recognition of polymorbidity as an important characteristic of geriatric medicine lead to important improvements in the multidisciplinary approach of the elderly. Coexistence of somatic and psychiatric diseases with various forms of etiopathogenic relations has been described early in this century. Dementia may be caused, aggravated, revealed or randomly accompanied by somatic diseases and inversely. However, very few attempts have been made in order to analyze the significance of these associations. This study is meant to give a better epidemiological knowledge of the relation between cardiovascular diseases and cerebral aging. This could lead to a better diagnostic approach and to a more complete physiopathological conception of dementia. 904 autopsy reports (patients who died between 1972 and 1986 in the Hôpital de Gériatrie of Genova) have been reviewed and classified in three groups according to neuropathological findings: 335 subjects with vascular encephalopathy of various types, 382 patients with degenerative diseases of Alzheimer type and 187 patients with normal brain. The subjects of these three groups had not all been considered demented. For each patient, age, sex, cause of death and 14 cardiovascular items have been appointed. The patients of the Alzheimer group died older and were more often women than those of the two other groups. The subjects of the vascular group died older than those of the normal group and were more often men than those of the two other groups. Stoke was considered to be the cause of death in 3% of the vascular patients whereas, by definition, it was absent from the two other groups.(ABSTRACT TRUNCATED AT 250 WORDS)

A computer-aided three-dimensional reconstruction of brain structures using high level computer graphics.

This paper describes how line drawings and continuous tone shaded images of a three-dimensional solid model of a brain structure are generated using a powerful general purpose computer graphics package. The model is built from a series of serial sections. We developed a software interface to convert the data entered by a section oriented way into a brain structure oriented file. We point out particularly the modular approach which consists of separating the tasks on small microcomputers or on bigger machines according to their computing cost. An example of a thalamic structure in a stereotaxic referential is presented.