Showing papers by "Boston University published in 1980"

Measuring health status in arthritis ; the arthritis impact measurement scales.

Abstract: A multidimensional index that measures the health status of individuals with arthritis has been developed. The Arthritis Impact Measurement Scales (AIMS) are a combination of previously studied and newly created health status scales which assess physical, emotional, and social well-being. The self-administered AIMS questionnaire has been pilot tested in a mixed arthritis population. Results indicate that the instrument is practical and that it generates scalable, reliable, and valid measures of both aggregated and disaggregated health status. The AIMS approach to health status measurement should prove useful for evaluating the outcomes of arthritis treatments and programs.

The Use of Sep‐Pak™ C18 Cartridges During the Isolation of Gangliosides

Abstract: The use of Sep-Pak C18 reverse-phase cartridges to adsorb gangliosides from aqueous solutions was studied When upper phases formed from chloroform-methanol tissue extracts or aqueous salt solutions containing gangliosides are rapidly passed through the cartridges, the lipids are retained and the non-lipid components can be washed through Gangliosides and other retained lipids can subsequently be eluted with methanol or chloroform-methanol

Some observations on oral air flow during phonation

Abstract: Reproducible intraoral air velocity measurements were made with a compact array of hot wire anemometers moved laterally within a vertical cross section at the rear of the mouth during sustained phonation of the vowel "I". The results indicate "separated" flow patterns at variance with laminar flow of vocal tract vowel models.

Large-cell Monte Carlo renormalization group for percolation

Abstract: We obtain the critical parameters for the site-percolation problem on the square lattice to a high degree of accuracy (comparable to that of series expansions) by using a Monte Carlo position-space renormalization-group procedure directly on the site-occupation probability. Our method involves calculating recursion relations using progressively larger lattice rescalings, $b$. We find smooth sequences for the value of the critical percolation concentration ${p}_{c}(b)$ and for the scaling powers ${y}_{p}(b)$ and ${y}_{h}(b)$. Extrapolating these sequences to the limit $b\ensuremath{\rightarrow}\ensuremath{\infty}$ leads to quite accurate numerical predictions. Further, by considering other weight functions or "rules" which also embody the essential connectivity feature of percolation, we find that the numerical results in the infinite-cell limit are in fact "rule independent." However, the actual fashion in which this limit is approached does depend upon the rule chosen. A connection between extrapolation of our renormalization-group results and finite-size scaling is made. Furthermore, the usual finite-size scaling arguments lead to independent estimates of ${p}_{c}$ and ${y}_{p}$. Combining both the large-cell approach and the finite-size scaling results, we obtain ${y}_{p}=0.7385\ifmmode\pm\else\textpm\fi{}0.0080$ and ${y}_{h}=1.898\ifmmode\pm\else\textpm\fi{}0.003$. Thus we find ${\ensuremath{\alpha}}_{p}=\ensuremath{-}0.708\ifmmode\pm\else\textpm\fi{}0.030$, ${\ensuremath{\beta}}_{p}=0.138(+0.006,\ensuremath{-}0.005)$, ${\ensuremath{\gamma}}_{p}=2.432\ifmmode\pm\else\textpm\fi{}0.035$, ${\ensuremath{\delta}}_{p}=18.6\ifmmode\pm\else\textpm\fi{}0.6$, ${\ensuremath{ u}}_{p}=1.354\ifmmode\pm\else\textpm\fi{}0.015$, and $2\ensuremath{-}{\ensuremath{\eta}}_{p}=1.796\ifmmode\pm\else\textpm\fi{}0.006$. The site-percolation threshold is found for the square lattice at ${p}_{c}=0.5931\ifmmode\pm\else\textpm\fi{}0.0006$. We note that our calculated value of ${\ensuremath{ u}}_{p}$ is in considerably better agreement with the proposal of Klein et al. that ${\ensuremath{ u}}_{p}=\frac{\mathrm{ln}\sqrt{3}}{\mathrm{ln}(\frac{3}{2})}\ensuremath{\cong}1.3548$, than with den Nijs' recent conjecture, which predicts ${\ensuremath{ u}}_{p}=\frac{4}{3}$. However, our results cannot entirely rule out the latter possibility.

Normative data on the boston diagnostic aphasia examination, parietal lobe battery, and the boston naming Test

Abstract: This report describes normative data for the Boston Diagnostic Aphasia Examination, the “Parietal Lobe Battery” (Goodglass & Kaplan, 1972), and the Boston Naming Test (Kaplan, Goodglass, & Weintraub, 1978). These tests were administered to 147 neurologically normal adult males, who were right-handed and native English-speaking. For each age and education group, means, standard deviations, and the range are reported. The lowest score for each group is suggested as a cut-off below which impairment may be suspected. Differences among age and education groups are specified and briefly discussed.

Prevalence of coronary heart disease in the framingham offspring study: Role of lipoprotein cholesterols

Abstract: Forty-three of 1,312 men aged 35 to 54 years in the Framingham Offspring Study had clinically recognized coronary heart disease at the initial examination. Twenty-six men in this group had previously had a myocardial infarction. Of 1,296 women in the same age range, only 11 had coronary disease and 3 a prior myocardial infarction. The prevalence of coronary heart disease in men was strongly associated with age, smoking, high density lipoprotein (HDL), low density lipoproteln (LDL) and total cholesterol using univariate analyses. When multivariate logistic regression analysis was used, age, smoking and HDL and LDL cholesterol retained their significant association with coronary heart disease. The total cholesterol/HDL cholesterol ratio was also strongly associated with coronary heart disease in the multivariate analysis. It is concluded that both HDL and LDL cholesterol are strongly and independently associated with the prevalence of coronary heart disease, whereas the level of very low density lipoprotein cholesterol makes no statistically significant independent contribution.

A new role for complement in experimental membranous nephropathy in rats.

Abstract: The only established role for complement in mediating immunologic renal disease involves elaboration of leukochemotactic factors and neutrophil-dependent glomerular injury. In the passive Heymann nephritis (PHN) model of experimental membranous nephropathy, rats injected with sheep antibody to rat proximal tubular brush border antigen (Fx1A) form subepithelial deposits of sheep IgG and rat complement (C3), and develop heavy proteinuria after 5 d without glomerular inflammatory changes. To study the role of complement in mediating proteinuria in PHN, 16 rats were treated daily with cobra venom factor from before antibody injection to maintain C3 levels at 0.5). Nephritogenic doses of both the noncomplement-fixing F(ab')2 portion and the gamma 2 subclass of anti-Fx1A IgG produced subepithelial deposits of immunoglobulin without C3, but proteinuria did not occur despite glomerular deposition of up to 70 microgram/2 kidneys of gamma 2. However, glomerular deposition of as little as 60 microgram of gamma 1 produced C3 fixation in vivo and heavy proteinuria. No neutrophil exudate could be detected histologically in PHN from the time of antibody injection through development of proteinuria. Proteinuria in five PHN rats depleted of neutrophils to 0.5). These results demonstrate that proteinuria in the PHN model of membranous nephropathy is complement-dependent and strongly suggest a neutrophil-independent mechanism. Thus a new role for the complement system in mediating immunologic glomerular injury is identified.

Interictal memory and language impairment in temporal lobe epilepsy.

Abstract: Memory and language were evaluated in patients with temporal lobe epilepsy and generalized epilepsy. Subjects were matched for age, duration of illness, and seizure frequency, and grouped according to the electroencephalographic results and seizure type into right temporal, left temporal, and generalized. In formal tests of intelligence, auditory and visual memory, and language, a significant difference was noted only on a confrontation naming test. The mean score on this test was considerably lower in the left temporal group; right temporal and generalized groups scored in the normal range. This correlated with impairment on many verbal subtests of intelligence and memory. These results suggest that the interictal memory impairment of temporal lobe epilepsy may be an anomia and that the anomia may contribute to impairment of verbal learning and memory; both circumlocution and circumstantiality may compensate for anomia.

Shedding from the Cell Surface of Normal and Cancer Cells

Abstract: Publisher Summary This chapter reviews the phenomenon of shedding of cell surface macromolecules, its role in normal membrane (glyco)protein turnover, and its importance in certain disease processes. Shedding is especially important in cancer cells where the release of cell surface components, such as proteases and adhesion molecules, occurs continually. The chapter discusses the cell surface of eukaryotic cells and the factors maintaining its stability; the synthesis, transport, and insertion of cell surface proteins and glycoproteins; and shedding during normal cell growth, its role in causing the phenotype of the mitotic cell, and its relationship to cell activation. It describes shedding from eggs, embryonic cells, retinal rods, lymphocytes, macrophages, and virus-infected cells. It also considers shedding from the cancer cell, as an extreme example of the activated cell, and the relationship between shedding and the cancer cell phenotype. Some possible consequences of shedding from the cancer cell is elucidated with respect to separation, infiltration, and metastases; abnormal hematological events such as enhanced coagulation and/or fibrinolysis and cryofibrinogenemia; immunological hyporesponsiveness and the role of various blocking and suppressor factors in its causation; and the appearance in the serum of certain enzymes such as glycosyl transferases that may be used for diagnostic purposes.

Learning and Memory Impairments in Young and Old Alcoholics: Evidence for the Premature‐Aging Hypothesis

Abstract: A battery of cognitive tests was administered to groups of younger (34--49) and older (50--59) alcoholics and nonalcoholic control subjects. Regardless of age, alcoholics were found to be impaired on essentially all measures of learning and memory. The relevance of these findings to the premature-aging hypothesis is discussed.

Heuristic lot-sizing performance in a rolling-schedule environment*

Abstract: This paper examines the impact of a rolling-schedule implementation on the performance of three of the better known lot-sizing methods for single-level assembly systems——Part-Period-Cost-Balancing, Silver-Meal, and Wagner-Whitin algorithms—and a modified version of the Silver-Meal procedure. The main finding is that under certain conditions the computationally simpler Silver-Meal heuristic can provide cost performance superior to that of the Wagner-Whitin algorithm.

Fatigue, recovery, and low back pain in varsity rowers.

Abstract: The purpose of this study was to determine whether surface electromyography (EMG) from the erector spinae muscles could correctly identify individuals with low back pain without a population of elite athletes. A similar technique had previously been successful in identifying low back pain patients within a non-athletic population. A Back Analysis System was used to compute the median frequency of the EMG power density spectrum to monitor metabolic changes in back muscles associated with muscle fatigue. Twenty-three members of a men's collegiate varsity crew team consisting of port (N = 13) and starboard (N = 10) rowers were tested in a laboratory during a fatigue-inducing isometric contraction sustained at a relatively high, constant force. Six of the rowers tested were further classified as having low back pain. A brief test contraction was repeated at a fixed interval following the fatiguing contraction to monitor recovery. A two-group discriminant analysis procedure correctly classified 100% of the rowers with low back pain and 93% of the rowers without back pain on the basis of the median frequency data. The median frequency parameters related to recovery were the best discriminators of back pain. A similar analysis correctly classified 100% of the port rowers and 100% of the starboard rowers on the basis of their spectral parameters. The best discriminating variables in this instance were the median frequency parameters relating to both fatigability and recovery. Results from this study demonstrate that low back pain and asymmetrical muscle function in rowers can be assessed on the basis of EMG spectral analysis.

Potassium conductance and internal calcium accumulation in a molluscan neurone.

Abstract: 1. The Aplysia neurone R-15 was injected with the Ca2+ sensitive dye arsenazo III. Changes in dye absorbance were measured with a differential spectrophotometer to monitor changes in the free internal Ca2+ concentration, [Ca]i, during membrane depolarization and during intracellular Ca2+ ion injection under voltage clamp conditions. 2. The absorbance change, and thus [Ca]i, increases linearly with Ca2+ injection intensity at constant duration. The absorbance change produced by a constant intensity Ca2+ injection also increases with injection duration, but this increase is asymptotic. 3. The Ca2+ activated K+ current, IK, Ca, increases linearly with the increase in [Ca]i and its rise and decay follows closely the time course of the absorbance change produced by internal Ca2+ injection. 4. The Ca2+ activated K+ conductance increases exponentially with membrane depolarization. The increase in K+ conductance activated by a constant intensity and duration Ca2+ injection is on average e-fold for a 25.3 mV change in membrane potential. 5. The difference in net outward K+ current measured during depolarizing pulses to different membrane potentials in normal and in Ca2+ free ASW was used as an index of IK, Ca. Its time course was approximately linear for the first 50-100 msec of depolarization, but for longer times the relation approached a maximum. Simultaneous measurements of the arsenazo III absorbance changes were broadly consistent with the activation of IK, Ca being brought about by the rise in [Ca]i during a pulse. 6. The relation between Ca2+ activated K+ conductance and membrane potential is bell shaped and resembles the absorbance vs. potential curve, but its maximum is displaced to more positive membrane potentials. The shift in the two curves on the voltage axis can be explained by the potential dependence of GK, Ca. 7. The net outward K+ current measured with depolarizing voltage pulses in normal and in Ca2+ free ASW is increased when [Ca]i is elevated by internal Ca2+ injection. With large and prolonged Ca2+ injections the net outward current is depressed following the decline of [Ca]i. 8. The time and frequency dependent depression of the net outward K+ current which occurs during repetitive stimulation is shown to have no obvious temporal relation to the increase in [Ca]i. The depression is relieved by an increase in [Ca]i caused by internal Ca2+ injection. 9. The net outward K+ current measured with brief depolarizing pulses which approach the estimated Ca2+ equilibrium potential and therefore do not cause Ca2+ influx and accumulation is facilitated by a previous depolarizing pulse which causes a rise in [Ca]i.. 10. The facilitation experiments also suggest that the activation of IK, Ca by [Ca]i has a significant time constant. During a depolarizing pulse, the rise in [Ca]i next to the membrane, and hence IK, Ca is expected to follow the square root of time, but a delay in the activation of IK, Ca by [Ca]i could explain why the observed time course of IK, Ca is initially almost linear. 11. The potential dependence of the Ca2+ activated K+ conductance can be explained if the internal Ca2+ binding site is about half way through the membrane.

The Role of Intergenerational Transfers in Aggregate Capital Accumulation

Abstract: This paper uses historicaI U.S. data to directly estimate the contribution of intergenerational transfers to aggregate capital accumulation. The evidence presented indicates that intergenerational transfers account for the vast majority of aggregate U .S. capital formation; only a negligible fraction of actual capital accumulation can be traced u, life-cycle or "hump" savings. A major difference between this study and previous investigations of this issue is the use of more accurate longitudinal age-earnings and age-consumption profiles. These profiles are simply too flat to generate substantial lifecycle savings. This paper suggests the importance of and need for substantially greater research and data collection on intergenerational transfers. fife-cycle models of savings that emphasize savings for retirement as the dominant form of apical accumulation should give way to models that illuminate the determinants of intergenerational transfers.

Narrative Strategies of Aphasic and Normal-Speaking Subjects

Abstract: A Picture Story Test for eliciting narrative speech was administered to five patients in each of the subgroups of Broca's and Wernicke's aphasic subjects and matched controls. While Wernicke's subj...

Biological competition: Decision rules, pattern formation, and oscillations

Abstract: This article summarizes some of the new mathematical and physical ideas about competition that have emerged during the past eight years. Each of these ideas can be expressed in several ways. For example, every competitive system induces a decision scheme that can be used to analyze its global dynamics. Otherwise expressed, you learn a lot about a competition by keeping track of who is winning it! Otherwise expressed again, you can understand more about certain nonequilibrium systems by measuring where they change fastest rather than where they achieve equilibrium. Still otherwise expressed, you can sometimes learn a lot about a continuous parallel process by embedding a discrete serial process into it, even though you couldn’t guess which serial process to embed without referring to the parallel process.

Three-dimensional aspects and synaptic relationships of a Golgi-impregnated spiny stellate cell reconstructed from serial thin sections

Abstract: A Golgi-impregnated spiny stellate cell was selected from layer IV of SmI cortex in a mouse whose ipsilateral ventrobasal complex had been lesioned. The neuron was gold-toned, thin sectioned and then reconstructed in three dimensions using wooden sheets of appropriate thickness. These procedures enabled the numbers and distribution of thalamocortical and other synapses onto the reconstructed neuron to be determined. Results show the cell body to be roughly spherical and to receive 49 symmetrical synapses and four synapses which are intermediate between the asymmetrical and symmetrical type. A single, clearly asymmetrical axosomatic synapse is made by a degenerating, thalamocortical axon terminal. Five primary dendrites and their branches were reconstructed and, interestingly, these processes are distinctly elliptical in cross-section. The reconstructed dendrites receive 68 symmetrical synapses onto their shafts and 373 synapses onto spines of which 359 are asymmetrical and 14 symmetrical. Forty-eight, or about 13%, of the asymmetrical axospinous synapses are made by degenerating, thalamocortical axon terminals. An intriguing finding is that in many regions of the dendritic tree, two or more spines involved in thalamocortical synapses are attached to the dendritic shaft at intervals of 5±0.5 μm.

Effects of d-amphetamine and naloxone on brain stimulation reward.

Abstract: Self-stimulation thresholds were determined in rats by means of a modification of the psychophysical method of limits. Reinforcement values were determined after the administration of d-amphetamine alone, naloxone alone, and naloxone administered concurrently with d-amphetamine. d-Amphetamine yielded dose-related decreases in the threshold (0.25–2.00 mg/kg IP), while naloxone alone (2.0–16 mg/kg IP) caused no consistent changes. For each animal, a dose of d-amphetamine that substantially lowered the threshold was then selected to be administered with varying doses of naloxone. The threshold-lowering effect of d-amphetamine was blocked by naloxone at doses as low as 2.0 or 4.0 mg/kg. This finding suggests the possible involvement of an opiate receptor in the mediation of the enhancement by d-amphetamine of brain stimulation reward.