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Biomedical subjects

D Goodman

Publications and source records attributed to D Goodman.

At least 19 recordsLinked to original sources
PubMed1992

Asymmetries in the spatial localization of transformed targets.

This study was designed to examine the contribution of the right cerebral hemisphere in the spatial localization of visual targets for manual aiming. Visual targets were briefly presented to the right and left fields and subjects were required to point either to the target location, or a "mirror" image of the target location with their right or left index finger. Whereas reaction times were faster for left-hand pointing than for right-hand pointing, there was no differential effect of the mirror image transformation. This suggests that left-hand reaction time advantages are more related to right hemisphere involvement in the spatial parameterization of the movement than spatial localization of the target.

Adult↗
PubMed1992

Asymmetries in the discrete and pseudocontinuous regulation of visually guided reaching.

An experiment was conducted to examine the contribution of the hemispheres to the organization of aiming movements. The spatial positions of targets were obtained by extrapolating from brief visual displays of geometric patterns. The patterns comprised linear, quadratic, cubic, and quartic mathematical functions and varied in spatial complexity. Vision of the hand was also manipulated. While the hands did not differ in spatial accuracy, movements made by the right hand were of shorter duration and had higher peak velocities. The stimulus pattern strongly influenced kinematics, in particular the number of discrete modifications of the movement trajectory. Vision of the hand resulted in superior accuracy, although subjects were unable to compare the relative positions of the limb and the target. Vision of the hand did not lead to an increase in discrete adjustments, suggesting that visual information was used in a continuous fashion. Movements into ipsilateral space differed from those into contralateral space with respect to a number of parameters.

Adult↗
PubMed1992

Treatment of antineutrophil cytoplasmic autoantibody-positive systemic vasculitis and glomerulonephritis with pooled intravenous gammaglobulin.

Antineutrophil cytoplasmic autoantibody (ANCA) is considered a serological marker for disease activity in patients with ANCA(+) systemic vasculitis. Recently, ANCA has been implicated as a pathogenic antibody that may be associated with neutrophil degranulation and release of lytic enzymes. Since intravenous gammaglobulin (IVIG) is known to contain antiidiotypic antibodies to ANCA, which could decrease the activity of the later, we chose to treat two patients with symptomatic ANCA(+) systemic vasculitis and glomerulonephritis with high-dose IVIG. The first patient, a 66-year-old man, developed rapidly progressive renal failure despite treatment with intravenous (IV) cyclophosphamide. The second patient, a 14-year-old boy, had relapsed 3 months after cessation of treatment with prednisone and cyclophosphamide. Both patients improved dramatically after treatment with IVIG, with the former recovering renal function within 11 days of therapy. In both patients, a concomitant reduction in serum ANCA titers was also observed. The second patient is currently in a sustained remission 14 months after his last IVIG dose on no other medication. These cases provide clinical evidence that IVIG has therapeutic benefit in modifying the immune-mediated injury associated with ANCA(+) systemic vasculitis and glomerulonephritis. In addition, IVIG may provide an additional safe therapeutic option to clinicians treating patient's with ANCA(+) vasculitis and glomerulonephritis who are not responsive to or are experiencing toxicity from conventional therapy.

Adolescent↗
PubMed1992

Fentanyl does not alter the "sleep" plasma concentration of thiopental.

Thiopental and fentanyl are commonly combined for induction of anesthesia. The effect of an analgesic concentration of fentanyl on the plasma concentration of thiopental to induce sleep was studied in 46 unpremedicated patients. As a measure of drug effect, sleep (the lack of response to open eyes to a verbal command) was used. Forty-six patients were randomized to receive thiopental infused to one of several predetermined plasma concentrations. Twenty-two of these patients also received a fentanyl infusion to a desired analgesic concentration of 1 ng/mL. Thiopental and fentanyl were infused by means of a pharmacokinetic model-driven infusion device (computer-assisted continuous infusion, CACI). Venous blood samples were taken from the contralateral antecubital fossa at 5 and 10 min after the start of the infusion. At 10 min, the patients' names were firmly spoken, and they were instructed to open their eyes. If they did not respond to this command, they were considered to be asleep. Only patients in whom the 5- and 10-min measured plasma concentrations of thiopental and fentanyl, respectively, were within +/- 30% of each other were used for the determination of the Cp50(asleep), the plasma concentration at which 50% of the patients were asleep. The Cp50(asleep) with and without fentanyl was calculated by logistic regression. The Cp50(asleep) for patients in whom concentrations were maintained within +/- 30% for thiopental alone (n = 17) was 7.32 micrograms/mL (95% confidence interval, 5.53-10.95); for thiopental in the presence of fentanyl (n = 18 with a measured fentanyl concentration of 1.27 +/- 0.5 ng/mL), this was 7.22 micrograms/mL (95% confidence interval, 4.83-10.15).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Effects of visual guidance on the reduction of impacts during landings.

While a common view is that vision is essential to motor performance, some recent studies have shown that continuous visual guidance may not always be required within certain time constraints. This study investigated a landing-related task (self-released falls) to assess the extent to which visual information enhances the ability to reduce the impacts at touchdown. Six individuals performed six blocked trials from four height categories in semi-counterbalanced order (5-10, 20-25, 60-65, and 90-95 cm) in vision and no-vision conditions randomly assigned. A series of two-way ANOVA with repeated measures were carried out separately on each dependent variable collapsed over six trials. The results indicated that vision during the flight did not produce softer landings. Indeed, in analysing the first peak (PFP) a main effect for visual condition was revealed in that the mean amplitude was slightly higher when vision was available (F(1,5) = 6.57; p less than 0.05), thus implicating higher forces at impact. The results obtained when the time to the first peak (TFP) was applied showed no significant differences between conditions (F(1,5) less than 1). As expected, in all cases, the analyses yielded significant main effects for the height categories factor. It appears that during self-initiated falls in which the environmental cues are known before the event, visual guidance is not necessary in order to adopt a softer landing strategy.

Adult↗
PubMed1991

Solitary polyclonal autonomous thyroid nodule: a rare cause of childhood hyperthyroidism.

Solitary autonomous thyroid tumors are an unusual cause of hyperthyroidism, particularly in childhood. We describe the youngest individual so far reported with this condition, a 22 month child with a large hyperfunctioning thyroid nodule who became overtly hyperthyroid after iodinated contrast administration. The histology of the nodule was compatible with follicular cell hyperplasia. These tumors are often called toxic adenomas, although there is no solid evidence that they are true neoplasms. We examined the clonal composition of the child's thyroid tumor by X-chromosome inactivation analysis, taking advantage of a polymorphism in the X-chromosome gene phosphoglycerate kinase. The tumor consisted of an even mixture of cells containing activated paternal and maternal PGK alleles, indicating that the tumor was polyclonal. Furthermore, the nodule had no structural rearrangements or activating point mutations of ras oncogenes, which are found in up to 50% of solitary monoclonal follicular adenomas. Solitary hot nodules may at least in some cases be secondary to hyperplasia, and not to clonal expansion of an abnormal, mutated cell. This may also explain the relatively low frequency of malignant transformation observed in hyperfunctioning thyroid tumors.

Adenoma↗
PubMed1991

Computerized continuous infusion of intravenous anesthetic drugs during pediatric cardiac surgery.

We evaluated the efficacy of a computer-assisted continuous infusion device (CACI) using a two-drug infusion of midazolam and sufentanil as an anesthetic technique during pediatric cardiac surgery. Seventeen pediatric patients were anesthetized with CACI using age-appropriate pharmacokinetic models for administering sufentanil and midazolam. Predicted CACI plasma concentrations were correlated with assayed plasma drug concentrations at eight predefined intervals. The accuracy was assessed using median absolute prediction error. We found that plasma levels predicted by CACI provided a reasonable approximation of measured plasma concentrations for both drugs. The median absolute prediction error for sufentanil during cardiopulmonary bypass was compared with measurements made off of cardiopulmonary bypass (both pre and post cardiopulmonary bypass) and were 49% and 32%, respectively, and for midazolam 44% and 32%, respectively. We conclude that (a) current kinetic models provide a reasonable estimate of plasma drug concentrations, and (b) the ease of administration and targeted plasma level provided by the CACI system is an alternative to inhalation anesthesia using calibrated vaporizers.

Adolescent↗
PubMed1990

Clinical utility of cycle exercise for the physiologic assessment of growth hormone release in children.

The clinical utility of exercise as a stimulus for the physiologic assessment of growth hormone (GH) deficiency was examined in healthy children. In response to exercise tests performed on different days, serum GH concentrations exceeded 7 micrograms/L on both days in 9 of 10 children. Although there is variation in this method of physiologic testing in the response of serum GH concentration (significant mean differences in GH peak values, 27.1 vs 19.8 micrograms/L for the two tests), the exercise test proved clinically valid in that diagnostic levels of GH were exceeded on both days 90% of the time. We conclude that this exercise evaluation protocol has clinical utility for the assessment of GH deficiency in children.

Adolescent↗
PubMed1990

The contribution of vision to asymmetries in manual aiming.

An experiment was conducted to examine the hypothesis that the right hand system is superior in the processing of visual information. A manual aiming task utilizing four visual conditions was employed. In the full-vision (FV) condition subjects were afforded vision of both the hand and the target throughout the course of the movement. In the ambient-illumination-off (AO) condition, the room lights were extinguished at movement initiation, thus preventing vision of the moving limb. The target remained illuminated. In the target-off (TO) condition, the target was extinguished upon initiation of the movement. Ambient illumination and thus vision of the hand remained present. Finally there was a no-vision (NV) condition in which ambient illumination was removed and the target was extinguished upon initiation of the response movement. Although the manipulation of vision had potent effects upon terminal accuracy, and influenced reaction and movement time measures, the hands did not differ in the extent to which these characteristics were expressed. A left hand advantage for reaction time was observed. This may reflect a relative increase in right hemisphere involvement prior to aiming movements which are spatially complex.

Adult↗
PubMed1990

Manual asymmetries in the reproduction of a 3-dimensional spatial location.

Two experiments examined differences in the reproduction of preselected arm positioning movements. In Experiment 1, subjects defined a position in right space with a right index finger, or a position in left space with the left index finger, and then attempted to reproduce the position with either the left or the right hand. Subjects were more accurate when vision was available and when the reproduction hand was the same as the criterion hand. Availability of vision reduced the same hand advantage. There were no accuracy differences between the left and right hands. Experiment 2 was designed to determine whether the left-left and right-right criterion and reproduction advantages evident in the no vision condition of the first experiment were accounted for by the two movements being made by the same hand or by being performed in the same space. The results demonstrated that accuracy depended primarily on whether movements were made with the same hand. No right/left hand advantage was observed. The absence of a right hand advantage in either experiment may be due to the spatial complexity of the task examined or to the relative absence of any temporal constraints.

Adult↗
PubMed1990

Simultaneous epiglottitis and parotitis: a case report.

A patient presenting to the emergency department with simultaneous parotitis and epiglottitis is described. She underwent emergency airway intervention within 3 hours of presentation. This is the first case of simultaneous parotitis and epiglotitis. Diagnostic symptoms are discussed.

Critical Care↗
PubMed1990

Dosimetric intercomparison in the British Institute of Radiology fractionation study of 3F/week versus 5F/week in radiotherapy of laryngo-pharynx cancer.

A dose intercomparison was carried out by the National Physical Laboratory between the seven radiotherapy centres which contributed the largest number of patients to the British Institute of Radiology fractionation study of three fractions per week versus five fractions per week in clinical cancer treatment. Six of the centres showed remarkable agreement within the acceptable limits of error of the measurements. In one centre there appeared to be a physical dose discrepancy of 2.8% which was materially less than could be detected clinically.

Humans↗
PubMed1990

Visual disabilities related to intraocular lens design.

Intraocular lens implantation after cataract extraction has become a common practice in the United States. However, unwanted optical images can correct an otherwise successful surgery into one that causes patient dissatisfaction. Refinements in manufacturing design and finishing have greatly improved the quality of present day intraocular lenses, but there is continued interest in simulating the optics of the human crystalline lens. We will discuss the optical requirements of intraocular lenses and how these are influenced by optic design and dimension, and spectral transmission characteristics.

Humans↗
PubMed1989

Genetic and molecular characterization of suppressors of SIR4 mutations in Saccharomyces cerevisiae.

In order to learn more about other proteins that may be involved in repression of HML and HMR in Saccharomyces cerevisiae, extragenic suppressor mutations were identified that could restore repression in cells defective in SIR4, a gene required for function of the silencer elements flanking HML and HMR. These suppressor mutations, which define at least three new genes, SAN1, SAN2 and SAN3, arose at the frequency expected for loss-of-function mutations following mutagenesis. All san mutations were recessive. Suppression by san1 was allele-nonspecific, since san1 could suppress two very different alleles of SIR4, and was locus-specific since san1 was unable to suppress a SIR3 mutation or a variety of mutations conferring auxotrophies. The SAN1 gene was cloned, sequenced, and used to construct a null allele. The null allele had the same phenotype as the EMS-induced mutations and exhibited no pleiotropies of its own. Thus, the SAN1 gene was not essential. SAN1-mediated suppression was neither due to compensatory mutations in interacting proteins, nor to translational missense suppression. SAN1 may act posttranslationally to control the stability or activity of the SIR4 protein.

Alleles↗