PubMed Health⌕ Search

Biomedical subjects

R Patterson

Publications and source records attributed to R Patterson.

At least 127 records · Page 7Linked to original sources
PubMed1993

Impedance cardiography: the failure of sternal electrodes to predict changes in stroke volume.

A study was conducted on 26 healthy male adults comparing the stroke volume (SV) and cardiac output (CO) measured with green dye and impedance cardiography in supine, sitting and during 50 W bicycle exercise. The impedance voltage pick-up electrodes were modified from the standard band location and placed at the suprasternal notch and 10 cm below. The percentage change of SV going from supine to sitting was -27.2 +/- 7.4% and -16.9 +/- 22% for the dye and impedance values respectively. The percentage change of SV going from sitting to exercise was 20.9 +/- 11.9% and 36.7 +/- 32.9% for the dye and impedance values respectively. The percentage change in SV determined by impedance shows poor correlation (supine to sitting R = 0.16 and sitting to exercise R = 0.42) with dye values. The individual impedance values for a given change in position or exercise showed considerably more variation compared with the dye. Impedance determination of SV using electrodes on the sternum does not appear to be a valid method for SV and CO measurements.

Adult↗
PubMed1993

Allergic bronchopulmonary mycosis caused by Pseudallescheria boydii.

Two cases of allergic bronchopulmonary pseudallescheriosis (ABPP) are described. These are the first cases of this allergic bronchopulmonary mycosis (ABPM) reported in which the clinical and serologic criteria are described. The first case was in a patient with mild asthma, and it resolved spontaneously after expectoration of a mucous plug. The second was in a patient with recurrent allergic bronchopulmonary aspergillosis with an exacerbation of ABPM caused by Pseudallescheria boydii. The total serum IgE, IgG, and IgE antibodies against P. boydii and the clinical picture well define ABPP. This diagnosis may be important to recognize in order to prevent a progression of the patient's lung disease.

Adult↗
PubMed1993

The application of an asthma severity index in patients with potentially fatal asthma.

The asthma severity index (ASI) is proposed as a tool to monitor the course of patients with increased risk of asthma-related morbidity and mortality. The ASI is a weighted summary of the diagnostic features of potentially fatal asthma (PFA). Fifteen patients with PFA were evaluated with ASIs calculated for the intervals 1 year prior to and 1 year following management by our allergy-immunology service. In each patient, a reduction was noted in the ASI following management, which corresponded to a reduction in asthma events. The ASI will have utility in the evaluation of chronic asthma treatment and in patient education.

Adolescent↗
PubMed1993

Passive transfer of IgE-mediated cutaneous reactivity in heterologous species.

The transfer of cutaneous hypersensitivity was performed in humans, monkeys, and dogs, using the Prausnitz-Küstner (PK) reaction. Quantitative endpoint titrations were used to study reactions resulting from sera from allergic humans, monkeys, and canines. IgE antibody from dogs sensitized human and rhesus monkey skin. IgE antibody from humans and rhesus monkeys did not sensitize canine skin. The Fc receptors on primate mast cells must have broader stoichiometric adaptation for IgE Fc receptors than the analogous Fc receptors on canine mast cells.

Animals↗
PubMed1993

Algorithms for the diagnosis and management of idiopathic anaphylaxis.

A major approach to the prevention of anaphylaxis due to exposure to an allergen is avoidance of the allergens. In cases of idiopathic anaphylaxis (IA), the method of management must first be pharmacologic control of the acute episode of IA and then the prevention of recurrent episodes. The appropriate management requires diagnosis, classification, and immediate initiation of a treatment regimen that will control and then induce a remission in patients with IA of the frequent (F) type. The classification and management of IA are reviewed and algorithms are presented for initial and long-term management of patients with IA.

Algorithms↗
PubMed1993

Immunologic specificity of IgG against trimellityl-human serum albumin in serum samples of workers exposed to trimellitic anhydride.

The specificity of immunoglobulin G (IgG) against trimellityl-human serum albumin (TM-HSA) in serum samples from 11 workers exposed to trimellitic anhydride (TMA) was characterized in this study. Levels of IgG against TM-HSA and HSA-conjugates of other acid anhydrides, phthalic anhydride (PA), maleic anhydride (MA), hexahydrophthalic anhydride (HHPA) and tetrachlorophthalic anhydride (TCPA) were estimated by enzyme-linked immunosorbent assay index. Inhibition studies using each of 5 HSA acid anhydride conjugates were performed on all 11 serum samples with IgG against TM-HSA, and on the three serum samples with highest IgG binding to P-HSA and M-HSA. The only conjugate capable of inhibiting TM-HSA was TM-HSA. Both P-HSA and TM-HSA were able to inhibit IgG bound to P-HSA, and all other anhydride conjugates were able to inhibit IgG bound to M-HSA to some degree. When using TM-HSA and the other anhydride-HSA conjugates to inhibit IgG against TM-HSA, cross-reactivity was not apparent. However, when using those same conjugates to inhibit IgG against P-HSA or M-HSA, cross-reactivity could be demonstrated in some serum samples. Thus TMA workers may have antibody that has some affinity for other anhydride-HSA conjugates, but this antibody cannot be demonstrated by inhibition studies of IgG against TM-HSA when using other acid anhydride-HSA conjugates. Further studies are needed to define the biologic relevance of these immunologic observations.

Adult↗
PubMed1992

Effects of myomas or prior myomectomy on in vitro fertilization (IVF) performance.

OBJECTIVE: The purpose of this study was to determine the effect of the presence of myomas and prior myomectomy on the pregnancy rate and pregnancy outcome in an in vitro fertilization (IVF) program. DESIGN: Data collected from office and hospital records were analyzed retrospectively. SETTING: Patients (all with private insurance carriers) were enrolled in an academic IVF program at The Jones Institute for Reproductive Medicine. PATIENTS: All IVF patients enrolled in series 26-41, from 1987 to 1990, were reviewed. Only patients with well-documented myomas [by laparoscopy, laparotomy, hysteroscopy, or hysterosalpingography (HSG)] or prior myomectomy (confirmed by operative and pathology report) were included. MAIN OUTCOME MEASURES: Pregnancy rates and pregnancy outcome were the main outcome measures. Pregnancy rates were calculated per preovulatory embryo transfer. Chi-square, Student t-test, and the Whitney-Mann test were used in the statistical analysis and P less than 0.05 was considered significant. RESULTS: Among 1415 IVF patients, 11 had confirmed myomas present and 47 others had prior myomectomies. The mean age of patients with myomas and myomectomy was 37.1 +/- 4.1 and 36.1 +/- 1.9 years, respectively. Ten of the patients with myoma had normal endometrial cavities on HSG. Subserosal tumors were present in 10 of 11 patients with myomas. Ten of the 47 myomectomy patients had an abnormal cavity prior to surgery and all were corrected. About half of the patients with prior myomectomy had subserous myomas, while 10% were submucous in location. Two of the patients had hysteroscopic removal; all the rest were performed abdominally. The ongoing pregnancy rate from fresh embryo transfer for patients with myomas and myomectomy was 20.8 and 16.9%, respectively. This was comparable to the 19.0% ongoing pregnancy rate for all patients in these series. Despite the small number, and the fact that most had subserosal myomas, patients with myomas had a 50% abortion rate, while those postmyomectomy had a 34.2% abortion rate (statistically not significant). Moreover, if subdivided by their primary IVF indications, patients with prior myomectomy had similar ongoing pregnancy rates from fresh embryo transfer compared to the whole IVF population. CONCLUSION: The incidence of myomas or prior myomectomy among infertility patients presenting for IVF was rather low. Myomectomy did not interfere with IVF performance in relation to overall and ongoing pregnancy rate.

Female↗
PubMed1992

Properties of cyclopean motion perception.

This study investigated the ability of human observers to discriminate the direction of laterally-moving cyclopean stimuli, in order to assess some of the properties of stereoscopic mechanisms that mediate the perception of cyclopean motion (motion existing at levels of binocular integration). The stimuli were moving grating patterns created from dynamic random-dot stereograms. Experiment 1 showed that duration thresholds for discrimination decrease with velocity; they are not governed by temporal frequency nor a constant spatial displacement. Experiment 2 revealed that discrimination thresholds increase with disparity magnitude, for both the crossed and uncrossed disparity directions equally. Experiment 3 showed that the rate of temporal variation at and above which direction discrimination fails (cyclopean upper limit of temporal resolution) is 8 Hz. Our results indicate that a mechanism for motion perception exists at binocular-integration levels of the visual system, which supports a model of motion perception that posits the existence of first-order and second-order processes.

Depth Perception↗
PubMed1992

Localization of inhaled trimellitic anhydride to lung with a respiratory lymph node antibody secreting cell response.

Male Sprague-Dawley rats were exposed to trimellitic anhydride (TMA) by inhalation (500 micrograms/m3), 4 hours a day, for 1 to 10 days. TMA was localized to lung cells by immunoelectron microscopy. Enzyme-linked immunosorbent assay (ELISA) and Western blot analysis were used in an attempt to localize TMA to lung lavage proteins. The lung-associated lymph node (LALN) B-lymphocyte response was measured by quantitation of immunoglobulin (Ig)G, IgA, and IgM antibody secreting cells specific for TMA rat serum albumin (TM-RSA) by use of the enzyme-linked immunospot assay (ELISPOT) method. The IgG, IgM, and IgA antibody response to TM-RSA in serum and lavage fluid was quantitated by ELISA. Lung injury was assessed by the number of external lung hemorrhagic foci and lung weight. Immunoelectron microscopy localized TMA to alveolar and bronchial cells on all exposure days. ELISA detected trace amounts of TMA haptenized lavage proteins that could not be detected by Western blot analysis. A marked increase occurred in lung injury from day 7 to 10. The LALN IgG, IgA, and IgM antibody secreting cell response to TM-RSA paralleled measures of lung injury. IgG, IgM, and IgA serum and lavage antibody to TM-RSA were correlated with lung injury measures. Lavage and serum IgG antibody levels had the highest correlation with lung injury.

Administration, Inhalation↗
PubMed1992

IgE-mediated rhesus monkey asthma: natural history and individual animal variation.

This report reviews the 20 years of experience with naturally occurring allergy in dogs and allergic rhesus monkeys. The primate model of allergy is characterized by IgE-mediated cutaneous and respiratory responses to Ascaris antigen. Individual assessments of these monkeys have been carried out over several years and separate populations which are analogous to human IgE-mediated allergic populations defined. These populations are as follows: (1) monkeys which have persistent and consistent IgE-mediated cutaneous and asthmatic responses to Ascaris antigen; (2) monkeys which have cutaneous and airway reactivity to Ascaris antigen but in which the airway reactivity subsides and disappears analogous to a spontaneous remission human asthma, and (3) finally, there is a group of animals with cutaneous reactivity but no asthma analogous to humans with a similar absence of asthma. Within these groups the animals, like humans, have individual variations of severity.

Animals↗
PubMed1992

Factors that affect depth perception in stereoscopic displays.

This study investigated several factors that affect depth perception in stereoscopic displays: half-image separation magnitude, separation direction (crossed vs. uncrossed), viewing distance, stimulus size, and exposure duration. The depth perceived under various combinations of levels of these factors was compared with depth predicted by the geometry of stereopsis. Perceived depth in the crossed-separation direction was frequently close to predictions, such that increases in separation and viewing distance produced appropriate increases in perceived depth. Depth in the uncrossed direction was frequently less than that predicted, especially for small stimuli presented at a long viewing distance, with a large half-image separation, and/or with a brief duration. Thus depth in both crossed and uncrossed directions equaled predictions only for large stimuli exposed for a long duration.

Adult↗
PubMed1992

Human stereopsis.

This paper reviews much of the basic literature on stereopsis for the purpose of providing information about the ability of humans to utilize stereoscopic information under operational conditions. This review is organized around five functional topics that may be important for the design of many stereoscopic display systems: geometry of stereoscopic depth perception, visual persistence, perceptual interaction among stereoscopic stimuli, neurophysiology of stereopsis, and theoretical considerations. The paper concludes with the presentation of several basic ideas related to the design of stereoscopic displays.

Animals↗