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Biomedical subjects

F Bookstein

Publications and source records attributed to F Bookstein.

13 recordsLinked to original sources
PubMed2000

Accelerated dysfunction among the very oldest-old in nursing homes.

BACKGROUND: The population aged 65 and older is often analyzed in three categories: young-old (65-74), middle-old (75-84), and oldest-old (> or = 85). This may blind heterogeneity within the oldest category. New, large data sets allow examination of the very oldest-old (e.g., aged > or = 95) and contrasts with those who are younger. METHODS: We determined the annual change of prevalence of physical and cognitive function, and of disease problems in the old to very oldest-old, using data from existing Resident Assessment Instrument records from nursing homes in seven states during 1992-1994. We used data from 193,467 unique residents aged 80 or older, including 6,556 residents aged 100 or older. We computed the prevalence, by age, of selected conditions: physical and cognitive function, diseases, problem behavior, mood disturbance, restraint use, falls, weight loss, eating less, body mass index, chewing and swallowing problems, incontinence (bowel and bladder), catheter use, and selected diagnoses. RESULTS: Prevalence of all measures of physical and cognitive dysfunction increased most rapidly with each year of age among the very oldest-old. Most of the slope changes occurred from 95 to 100 years of age. Such changes are less pronounced or not seen in measures of disease prevalence. CONCLUSIONS: Accelerated change in prevalence of dysfunction seen in the nursing home population may suggest a change in the mechanisms of aging that occur after the mid-nineties. Examination of the very oldest-old may provide new insight into the nature of the aging process.

Activities of Daily Living↗
PubMed1999

Comparing frontal cranial profiles in archaic and modern homo by morphometric analysis.

Archaic and modern human frontal bones are known to be quite distinct externally, by both conventional visual and metric evaluation. Internally this area of the skull has been considerably less well-studied. Here we present results from a comparison of interior, as well as exterior, frontal bone profiles from CT scans of five mid-Pleistocene and Neanderthal crania and 16 modern humans. Analysis was by a new morphometric method, Procrustes analysis of semi-landmarks, that permits the statistical comparison of curves between landmarks. As expected, we found substantial external differences between archaic and modern samples, differences that are mainly confined to the region around the brow ridge. However, in the inner median-sagittal profile, the shape remained remarkably stable over all 21 specimens. This implies that no significant alteration in this region has taken place over a period of a half-million years or more of evolution, even as considerable external change occurred within the hominid clade spanning several species. This confirms that the forms of the inner and outer aspects of the human frontal bone are determined by entirely independent factors, and further indicates unexpected stability in anterior brain morphology over the period during which modern human cognitive capacities emerged. Anat Rec (New Anat): 257:217-224, 1999.

Biometry↗
PubMed1998

Age-related changes in regional cerebral blood flow during working memory for faces.

Young and old adults underwent positron emission tomography during the performance of a working memory task for faces (delayed match-to-sample), in which the delay between the sample and choice faces was varied from 1 to 21 s. Reaction time was slower and accuracy lower in the old group, but not markedly so. Values of regional cerebral blood flow (rCBF) were analyzed for sustained activity across delay conditions, as well as for changes as delay increased. Many brain regions showed similar activity during these tasks in both young and old adults, including left anterior prefrontal cortex, which had increased rCBF with delay, and ventral extrastriate cortex, which showed decreased rCBF with delay. However, old adults had less activation overall and less modulation of rCBF across delay in right ventrolateral prefrontal cortex than did the young adults. Old adults also showed greater rCBF activation in left dorsolateral prefrontal cortex across all WM delays and increased rCBF at short delays in left occipitoparietal cortex compared to young adults. Activity in many of these regions was differentially related to performance in that it was associated with decreasing response times in the young group and increasing response times in the older individuals. Thus despite the finding that performance on these memory tasks and associated activity in a number of brain areas are relatively preserved in old adults, differences elsewhere in the brain suggest that different strategies or cognitive processes are used by the elderly to maintain memory representations over short periods of time.

Adult↗
PubMed1997

Candidate biomarkers of aging: age-sensitive indices of immune and muscle function covary in genetically heterogeneous mice.

A longitudinal experiment was designed to test the hypothesis that individual mice differ in their aging rate and to validate candidate biomarkers proposed to measure the rate of aging. Mice were bred as the genetically heterogeneous progeny of a cross between CB6F1 mothers and C3D2F1 fathers. Half of the mice were fed ad libitum (AL group), and the other half were subjected to 60% calorie restriction (CR group). Each mouse was tested at about 9 months of age using age-sensitive tests of immune status, and then again at about 12 months of age using age-sensitive tests of muscle function. The data were then analyzed using the method of partial least squares to determine the combinations of test weights that maximize the covariance of the weighted sum of immune measures with the weighted sum of muscle function measures. Both AL and CR mice exhibited a statistically significant relation between the immune status tests and the muscle function tests. Maximal covariance was obtained with a set of weighting coefficients consistent with our working hypothesis: mice with high levels of CD4 memory T cells (which increase with age) also had relatively low levels of muscle strength and endurance. Low strength was associated with low CD8 cells in the AL mice, with high numbers of CD8 memory cells in the CR mice and with low CD3 cells in both diet groups. The partial least squares method generates composite indices of immune status and muscle function that can be evaluated as biomarkers of aging rate in these mice. Further work will be needed to assess whether these tests predict either longevity or the trajectory of change in other age-sensitive molecular and physiological traits.

Aging↗
PubMed1991

Relating structure to function in vivo with tomographic imaging.

For the normal physiological responses of the brain or the pathophysiological changes that accompany disease states to be evaluated, it is necessary to compare data sets between different imaging modalities for individual subjects. Similarly, it is important to compare data between individuals both within and across imaging modalities for individual subjects. In a collaborative project with a number of university groups we have developed a system that allows for the within-subject alignment and registration of three-dimensional data sets obtained from different modalities for the same individual. This analysis takes into account the error induced by image acquisition, registration and alignment with regard to scaling, translation and rotation. A more difficult problem is the between-subject warping of individual brain anatomy to match that of another individual or of an idealized model. If the principles of morphometrics and homologous landmarks are applied, three-dimensional brain warping can provide this type of between-subject comparison. The results of accomplishing these two tasks is a system that allows data obtained in a given individual to be compared across structure and function, as obtained from magnetic resonance imaging (MRI) and from positron emission tomography (PET), respectively. It also allows comparison of the resultant information with averaged between-subject data from populations of normal individuals or patients with specific neurological disorders. This system provides the means by which to compare quantitative data between individuals in an objective and automated fashion.

Algorithms↗
PubMed1986

Adrenal tissue characterization using MR imaging.

Using a superconducting magnet operating at 0.35 T, the authors investigated the adrenal tissue characterization potential of magnetic resonance (MR) in 28 patients with 33 adrenal masses. There were 13 adrenal adenomas (12 non-hyperfunctioning, one aldosteronoma), nine adrenal metastases, four pheochromocytomas, two neuroblastomas, two adrenal lymphomas, two myelolipomas, and one adrenal cortical carcinoma. Spin-echo pulse sequences were obtained at TR 0.5, 2.0 sec and TE 28, 56 msec. Both qualitative (visual assessment) and quantitative (absolute signal intensity, intensity ratios, T1, T2) data were used for tissue characterization. The results suggest that non-hyperfunctioning adrenal adenomas can be distinguished from non-adenomas using both qualitative and quantitative data: 16/19 non-adenomas were visually hyperintense compared with liver at TR 2.0 sec, TE 56 msec, while none of the non-hyperfunctioning adenomas was relatively hyperintense at any pulse sequence used. Of the quantitative data, the intensity ratios of adrenal lesion/liver at TR 0.5 sec, TE 56 msec were most useful in diagnosis: all adenomas had ratios less than 0.83, while 19/20 non-adenomas had ratios exceeding this value. It is concluded that MR has considerable promise in adrenal tissue characterization.

Adenoma↗
PubMed1984

Le Fort III advancement osteotomy in the growing child.

A prospective clinical and cephalometric study was conducted on 12 patients under the age of 12 years undergoing Le Fort III advancement with the following findings: 1. There was a remarkable degree of postoperative skeletal stability of the midfacial segment. 2. Disharmony in jaw relationship (anterior crossbite) observed during the period of longitudinal postoperative study could be attributed to expected mandibular development. 3. In some patients, growth and development of the maxilla in a forward and downward direction were documented after Le Fort III advancement. The authors recommend that a Le Fort III advancement can be safely performed at approximately age 4 without a deleterious effect on midfacial development in the patient with craniofacial dysostosis.

Cephalometry↗
PubMed1983

Analysis of craniofacial asymmetry by multiplane cephalometry.

A three-dimensional, multiplane cephalometric analysis is presented. This analysis permits visualization of skeletal midlines at selected depths of the craniofacial complex. When the midlines and associated anatomic structures are studied sequentially, the individual midlines may be combined conceptually into a warped midsagittal "plane." This localizes craniofacial asymmetry in the posteroanterior and basilar views. The study of structures in various coronal and transverse planes makes it possible to measure and record the three-dimensional relationships of anatomic structures to one another. A case of hemicraniofacial microsomia in which this analysis was used is presented.

Cephalometry↗
PubMed1977

Effect of high-concentration ammonium and sodium fluoride rinses on dental caries in schoolchildren.

A double-blind clinical trial was conducted in a non-fluoridated community to determine the effect on enamel fluoride and caries experience of daily rinsing in school with 1,000 parts/10(6) solutions of ammonium fluoride or sodium fluoride at pH 4.4. Subjects were 10- to 12-year-old children (n approximately equal to 200/group at baseline), about one-half of whom reported the usage of fluoride supplements. Dental caries (DFS index) and enamel fluoride (in vivo biopsy) were evaluated at baseline, 12 months, and 24 months. Supplement users had higher enamel fluoride levels and less caries experience initially, as well as generally lower caries increments over the study. In year 1, the overall caries reductions (supplement users and non-users combined) were 23 % (ammonium fluoride) and 33 % (sodium fluoride), P less than 0.01. For year 2, treatment effects were significantly greater: 54 % (ammonium fluoride) and 47 % (sodium fluoride). In newly erupted teeth, the effects of the ammonium fluoride (70 % DFS reduction) was significantly greater (P = 0.013) than that of the sodium fluoride (48 % DFS reduction). Enamel fluoride levels at the end of 2 years were 3,124 parts/10(6) (ammonium fluoride), 2,771 parts/10(6) (sodium fluoride), and 2,603 parts/10(6) (placebo), P = 0.025.

Child↗