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Biomedical subjects

B Byrne

Publications and source records attributed to B Byrne.

At least 55 records · Page 3Linked to original sources

Learning artificial orthographies: further evidence of a nonanalytic acquisition procedure.

Previous research (Byrne, 1984) showed that adults who learned to read an orthography representing phonetic features (voicing, place of articulation) did not readily obtain usable knowledge of the mapping of phonetic features onto orthographic elements, as evidenced by failure to generalize to partially new stimuli. The present Experiment 1 used a different method of detecting learning savings during acquisition. Subjects learned a set of complex symbols standing for phones, with the elements representing voicing and place. In a second acquisition set, the signs for voicing were reversed. Learning speed was not affected, which was consistent with the claim that feature-element links went unnoticed in initial acquisition. In Experiment 2, some subjects were instructed to "find the rule" embodied in the orthography. None did, and acquisition rates were no different from those of uninstructed subjects. In Experiment 3, subjects had 4 h of training on the orthography, with consistent feature-symbol mapping for half of the subjects and arbitrary pairings for the remainder. No reaction time advantage emerged in the consistent condition, which is further evidence of nonanalytic acquisition. The results are related to data from children learning to read.

Cues↗

Effects of routine pupillary dilation on functional daylight vision.

The visual acuity of 100 patients between the ages of 16 and 66 years, seen for routine ophthalmologic examination, was measured before and after dilation. All patients had a predilation visual acuity of 20/40 or better. Postdilation binocular visual acuity using the patients' usual correction was measured first in the office and then outdoors, both with the patient's back to and the patient facing the sun, with and without the aid of postmydriatic sunglasses. Twelve percent experienced disabling photophobia even with the use of postmydriatic sunglasses, with 3% having significant objective visual loss defined as 20/50 or worse. No objective visual loss was found in 30 controls examined outdoors before dilation, without sunglasses. We recommend that patients who have experienced significant photophobia with dilation in the past, or who have never before undergone dilation, make arrangements for transportation after a dilated examination.

Adolescent↗

Anti-human immunodeficiency virus type 1 antibody complexes on platelets of seropositive thrombocytopenic homosexuals and narcotic addicts.

Patients with human immunodeficiency virus type 1 (HIV-1) infection develop an immunologic thrombocytopenic purpura associated with markedly elevated platelet IgG, IgM, and C3C4 as well as serum immune complexes determined by the polyethylene glycol (PEG) method. Analysis of their serum PEG-precipitable immune complexes as well as platelet acid eluates revealed the presence of anti-HIV-1 antibody existing as a complex that eluted in the void volume of a Sephadex G-200 gel-filtration column. The complex binds to washed normal platelets, whereas affinity-purified anti-HIV-1 (gp120) antibody does not. HIV-1 antigen or proviral DNA was not detectable in the immune complexes or platelet extracts. However, anti-antibodies directed against anti-HIV-1 antibody were detectable in the immune complexes as well as platelet eluates. Approximately 50% of eluted platelet IgG contained anti-HIV-1 antibody. Thus the markedly elevated platelet immunoglobulin is partly due to the presence of anti-HIV-1 antibody complexes. This may be responsible for the enhanced platelet clearance and thrombocytopenia in patients with acquired immunodeficiency syndrome-related immunologic thrombocytopenia.

Acquired Immunodeficiency Syndrome↗

Extraocular muscle size comparison using standardized A-scan echography and computerized tomography scan measurements.

In many clinical situations, the standard for evaluating extraocular muscle (EOM) size, particularly in thyroid ophthalmopathy, has been use of the computerized tomography (CT) scanner. The impression is generally reported as "enlarged or normal EOMs." If the report of "normal EOM" on CT scan weighs heavily against the diagnosis of thyroid eye disease, how does this qualitative assessment compare with the diagnostic modality of ultrasound? The technique of standardized A-scan measurement of extraocular muscles has been extremely accurate. In this paper, standardized A-scan measurements and CT scan estimates of EOMs are compared in a series of ten patients with a clinical diagnosis of Graves' disease. Three of ten patients displayed enlarged EOMs by CT interpretations; seven of ten patients were categorized as consistent with Graves' disease by correlation with current ultrasonographic criteria for muscle enlargement, asymmetry, and high irregularity of tissue reflectivity.

Exophthalmos↗

Analysis of B-cell antigens in normal reactive lymphoid tissue using four B-cell monoclonal antibodies.

Lymph nodes from 13 cases of reactive hyperplasia were examined with four different monoclonal antibodies to B cells. B-1 recognizes an antigen of 30,000 daltons on B cells. CB-2 was prepared with normal spleen and binds to a glycolipid. BA-1 labels surface immunoglobulin-positive cells, but not T lymphocytes or monocytes. B-532 recognizes an antigenic determinant of 45,000 daltons. Using the immunoperoxidase method on frozen sections of reactive lymph nodes, the staining patterns of these four unique antibodies showed dramatic differences. B-1 labeled 80%-90% of the germinal center cells and 10%-50% of the mantle region. Few interfollicular cells were positive. CB-2 stained predominantly in the mantle area (50%-90% positive cells), with moderate staining in the germinal center as well and less than 1% positive cells in the diffuse cortex. BA-1 exhibited predominant labeling in the mantle (50%-90%), with little staining in the germinal center. A large number of cells in the interfollicular, subcapsular, and medullary regions expressed the BA-1 antigen. The B-5 antibody demonstrated intense staining in the follicle (50%-95%). This staining often appeared to be polarized within the germinal center. The mantle zone demonstrated staining of 30%-50% of the cells. The different staining patterns of the B-cell antibodies, as demonstrated by the in situ distribution of positive cells within the lymph node, may reflect stages of development or activation of the B-cell population.

Antibodies, Monoclonal↗

Influence of novel male on the social behaviour of a captive group of mature female long-tailed macaques (Macaca fascicularis).

The replacement of a sexually mature, but sexually inactive, male by a novel mature male in a small colony of Macaca fascicularis brought about changes in social behaviour and structure. Particularly striking were the heightened levels of all sexual activity, especially in the females' invitation to the male to copulate. Cohesiveness around the male increased. Increased levels of agonism were noted and changes in the agonistic female hierarchy resulted. The grooming relationships in the colony were also significantly altered.

Aggression↗

General characteristics of protein degradation in diabetes and starvation.

The enhanced protein degradation associated with diabetes and starvation is fundamentally different from normal protein catabolism. In normal eukaryotic cells large molecular weight proteins tend to be degraded more rapidly than small proteins, acidic proteins tend to be degraded more rapidly than neutral or basic proteins, and glycoproteins tend to be degraded more rapidly than nonglycoproteins. All three of these general correlations are absent or markedly reduced in liver and muscle of diabetic and starved rats. In contrast, the correlations between proteins size and half-life, between protein net charge and half-life, and between protein carbohydrate content and half-life are not affected in brain of diabetic or starved animals. These results suggest that diabetes and starvation alter the general characteristics of intracellular protein degradation in target tissues of insulin. Degradation of serum proteins is also affected in diabetes and starvation. In normal animals a general correlation exists between isoelectric points of serum proteins and their degradative rates. This relationship is abolished in diabetes and starvation, as it is among liver and muscle proteins. The implications of our findings are discussed with regard to possible mechanisms of the enhanced protein breakdown.

Animals↗

Cognitive style and lateral eye movements.

The lateral eye movement paradigm was employed to test the hypothesis that narrow categorizers, who are believed to be more analytic in information processing, make characteristic use of the left hemisphere, while broad categorizers, being more holistic, depend more on the right hemisphere. Data for narrow categorizers confirmed the hypothesis in that they tended to produce a majority of right shifts. Results from broad categorizers turned out to be less clear, although there was a tendency in the direction of left eye shift. Additionally, narrow categorizers made significantly more total LEMs than did broad categorizers. The results are discussed in terms of cerebral specialization underlying cognitive style.

Cognition↗

Deep vein thrombosis prophylaxis: the effectiveness and implications of using below-knee or thigh-length graduated compression stockings.

Potential complications of reduced mobility in both acute and chronically ill patients continue to challenge nurses on a daily basis. Deep vein thrombosis (DVT) is one of the most serious of these complications. Graduated compression stockings, also known as antiembolism stockings, are among the most commonly available and accepted methods of external compression for the prophylaxis of DVT. Currently, there are 2 lengths of graduated compression stockings in common use, thigh-length and below-knee. Although thigh-length stockings are widely perceived to be more effective in prophylaxis, difficulties associated with therapeutic application and maintenance are often encountered in different clinical settings. Below-knee stockings are easier to apply and maintain and appear to be tolerated better by patients. The aim of this article is to examine existing support for both lengths of stockings in terms of their effectiveness in DVT prophylaxis and to discuss the implications for practice.

Bandages↗