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Biomedical subjects

J Cooper

Publications and source records attributed to J Cooper.

At least 487 records · Page 27Linked to original sources

Microcomputer produced anaglyphs for evaluation and therapy of binocular anomalies.

An Atari 800 microprocessor with a color television monitor was used to produce red-green anaglyphs. These computer produced anaglyphs allow for rapid manipulation of vergence stimuli which allow the doctor greater control in diagnosis and therapy of binocular anomalies. Additionally, computer controlled stimuli allow for animation, and delivery of reinforcing aspects. The present paper describes a system in use.

Computers↗

Limulus lysate assay in detection of gonorrhea in women from a low-incidence population.

An evaluation of the limulus amebocyte lysate assay for detection of gonococcal endotoxin in cervical secretions was undertaken in 48 women from an ambulatory population with a low incidence of gonococcal infection. When cervical secretions were diluted 1 : 2,000, positive limulus amebocyte lysate assay results were obtained in four women (100%) with culture-proved gonococcal infection, and negative results were obtained in 25 of 44 women (57%) with culture-negative specimens. The limulus amebocyte lysate assay was not sufficiently specific in a low-incidence, largely asymptomatic population to be recommended as a rapid diagnostic procedure (60 minutes) in such a group. Standardization of sampling technique, size, and reagent preparation and elimination of vaginal contamination of cervical secretions may produce a limulus amebocyte lysate test with more consistent performance characteristics in varied populations. Since the predictive value of a test varies with the prevalence of the disease in the populations tested, a test proposed for use in a population with a low likelihood of disease must be tested in such a population.

Adolescent↗

Reflexivity and countertransference in a psychiatric cultural consultation clinic.

A Mexican-American woman who complained of persistent head pain and a bothersome "voice" was seen by a team consisting of a psychiatrist, social scientists, and spiritualist healers in a Cultural Consultation Clinic of a Psychiatric Consultation Liaison Service. This single case is analyzed to provide an understanding of the interpretive dimensions of psychiatric practice. It is argued that a hermeneutic analysis of clinical phenomena focuses attention on three distinct aspects of interpretation: on the interpretation by clinicians and clients of the discourse of the other in terms of their own clinical models; on the influence of deeply embedded personal meanings on this interpretive process; and on the role of the observer in clinical ethnography. It is argued that to sustain a hermeneutic analysis of psychiatric practice, an account of transference and countertransference in terms of interpretation theory will have to be developed.

Adult↗

Cellular chemical indices of right ventricular protection in children.

Myocardial preservation during open heart surgery in children was studied using biopsies of the right ventricle taken at the beginning and end of a bypass with a Tru-Cut biopsy needle. Three assessments were used: (1) semi-quantitative cytochemical grading of Baker's acid haematein reaction, and the distribution of succinate dehydrogenase and myosin ATPase; (2) microdensitometry of the succinate dehydrogenase activity; and (3) quantitative birefringence measurements to assess the response of the myocardial fibres to ATP and calcium. For each assessment, the values at the beginning and end of the bypass were compared. In a series of 42 children, two died in low cardiac output and three others required substantial inotropic support. No patient showed deterioration in the overall cytochemical assessment. Two patients showed deterioration in birefringence, one died and one had low cardiac output. The remaining three patients who had post-operative problems had low birefringence values at the beginning of bypass. Thirty-two patients were used for the microdensitometric assays, one died and three required substantial inotropic support. Succinate dehydrogenase activity decreased significantly during bypass in only two patients. One of these died and the other required substantial inotropic support.

Adenosine Triphosphatases↗

Stimulus and response AC/A ratios in intermittent exotropia of the divergence-excess type.

Objective infrared recording devices were used to measure simultaneously and continuously both accommodation and accommodative vergence to near stimuli in 4 subjects with intermittent exotropia of the divergence-excess type (2 simulated and 2 true). In addition standard clinically determined stimulus accommodative convergence to accommodation (AC/A) ratios were measured. Results showed the mean group response AC/C ratio to be 5.9/1 (range 4.5-8.0/1) with no differences between true and simulated divergence-excess. Similar AC/A ratios were found after 45 minutes of monocular occlusion. Our results clearly demonstrate relatively normal response AC/A ratios in these subjects. Thus, contrary to what is believed by many clinicians, the reduced ocular deviation at near compared with distance vision cannot be attributed primarily to an abnormally high AC/A ratio. We believe than fusional convergence after-effects and/or proximal convergence effects contribute to inflate the clinically determined stimulus AC/A ratios.

Accommodation, Ocular↗

Management of mandibular fractures using biphasic pins and mandibular splints.

Often the otolaryngologist is asked to manage the patient with facial trauma. Mandibular fractures make up 20 to 39% of all facial trauma cases, and thus necessitate a diversified and complete set of management tools. We have selected two seldom discussed modes of therapy for the complicated jaw fracture to present in this paper: 1. external fixation of Joe-Morrison Hall biphasic pins, and 2. mandibular dental appliances--splints. The advantage of the biphasic pin apparatus is that the fracture can be repaired and stabilized at a point remote from the infected fracture site. The high risk patients, endentulous patient, and patients with fractures from gunshot wounds all prove to be more easily managed by using the external appliances. The splint technique eliminates medial or lingual tip rotation and resultant postoperative malocclusion. Endentulous patients, pediatric patients, and those with multiple facial trauma also benefit from this procedure.

Acrylic Resins↗

Mortality rate in strabismus surgery.

Strabismus surgery has been viewed as being associated with a high degree of mortality. Many past studies have used small surgical samples and have stressed the various theoretical causes of the deaths rather than view the procedure from a statistical and scientific standpoint. We present here a large series of surgical cases collected nationwide showing that strabismus surgery is a relatively safe procedure associated with a mortality less than that of a tooth extraction.

Adolescent↗

Prevention of recurrent urinary infections in women: a comparative trial between nitrofurantoin and methenamine hippurate.

We treated 99 female patients suffering from recurrent urinary infections with either 1 gm. methenamine hippurate every 12 hours or 50 mg. nitrofurantoin every 12 hours for intervals of up to 1 year. Monthly microbiological and clinical surveillance was done. Both treatments were effective in reducing the incidence of symptomatic attacks, with nitrofurantoin being more effective. The protective effect of prophylaxis continued after treatment had stopped, suggesting that a permanent beneficial action had been produced. Especially during the first month of treatment methenamine hippurate was tolerated better than nitrofurantoin: 28 per cent discontinued therapy with the latter owing to nausea.

Adult↗

Reliability of fixation disparity curves.

Fixation disparity curves were recorded in three normal subjects once per week over a period of 10 weeks. Results indicate that measurements of fixation disparity are reliable within limited ranges of forced convergence and forced divergence. Increases in the demand to maintain fusion lead to increases in observed variability of fixation disparity. It is suggested that variability of fixation disparity might be related to the ease with which the two eyes are used as a team.

Adult↗

Gender constancy and the effects of sex-typed televised toy commercials.

The present study represented a cognitive-developmental analysis of the effects of televised, sex-stereotypic information on children's behavior and attitudes toward toy play. The subjects were 50 male and 50 female 4-6-year-olds divided into high and low gender-constancy levels. As the children watched a cartoon, they either saw a commercial of a gender-neutral toy that showed 2 boys or 2 girls playing with the toy, or they saw no commercial (control). As predicted, only the high gender-constant children were differentially affected by the sex-role information in the different commercial conditions. Children at this stage who saw opposite-sex children playing with the toy avoided spending time with the toy and stated verbally that the toy was more appropriate for an opposite-sex sibling, relative to children in the 2 other conditions. The results are discussed in terms of their implications for theories of sex-role development and in terms of the role that television may play in maintaining sex stereotypes and sex-typed behavior.

Advertising↗

Effects of pseudoephedrine and triprolidine, alone and in combination, on symptoms of the common cold.

A total of 466 healthy adults from four different regions of England entered a double-blind, randomised trial to test the effectiveness of an antihistamine (triprolidine) and a decongestant (pseudoephedrine), alone or in combination, in relieving symptoms of the common cold. During the study 199 subjects reported a total of 243 colds. Subjects recorded the severity of 12 symptoms during treatment and noted separately the severity of a further seven symptoms that represented unwanted effects of treatment or served as an index of suggestibility. They were then asked about their overall improvement in symptoms during treatment and whether they thought they had taken placebo. Sneezing, nasal obstruction, and overall response to treatment were significantly improved (p <0.01) with psuedoephedrine or pseudoephedrine and triprolidine compared with placebo.

Clinical Trials as Topic↗

Acetylcholine receptors from Torpedo and Electrophorus have similar subunit structures.

Previously, acetylcholine receptor purified from the electric organs of electric eels (Electrophorus electricus) and electric rays (Torpedo californica) (torpedo) had appeared to differ in subunit structure. Receptor from torpedo has the subunit structure alpha 2 beta gamma delta, but subunits corresponding only to alpha, beta, and gamma had been observed in receptor from eel. Here we report that if membrane fragments of eel electric organ are prepared and detergent extracted in the presence of iodoacetamide, then receptor purified from the extract contains a fourth subunit. Using monoclonal antibodies as well as conventional antisera, we show that the newly recognized subunit of receptor from eel corresponds to the delta subunit of torpedo. A monoclonal antibody to the delta subunit of torpedo cross-reacts with the gamma subunit and shows a similar cross-reaction between the delta' and gamma' subunits of receptor from eel, indicating the presence of an unexpected structural similarity. Although the function of the beta, gamma, and delta subunits remains unknown, these results support the concept that receptors from the electric organs of several species and probably also from muscle share a similarly complex subunit structure.

Acetylcholine↗

The management of nonmalignant intrathoracic esophageal perforations.

Eight patients with nonmalignant intrathoracic esophageal perforations recognized more than 48 hours (48 hours to 14 days) after rupture were treated at Toronto General Hospital between 1973 and 1978. Perforation was due to postemetic rupture in 7 patients and to instrumentation in 1. The patients were seen with pain (8), vomiting (7), fever (7), shock (4), respiratory insufficiency (5), pleural effusion (7), pulmonary infiltrates (7), and leukocytosis (6). All patients were managed with thoracotomy. Direct suture closure of the perforation was carried out in 4 patients with midesophageal perforations. Postoperative localized leaks developed in 2 of these patients but healed with conservative management. Cervical esophagostomy and esophageal diversion were used in 1 patient in whom a severe empyema developed in the postoperative period. Direct suture closure, reinforced with a gastric patch, was used to close three lower esophageal perforations. None of these patients had a postoperative leak but all developed subsequent reflux esophagitis. All 8 patients survived. In patients with delayed recognition of a nonmalignant intrathoracic esophageal perforation, elimination of continued chemical and bacterial contamination can be achieved by a clear definition and closure of the esophageal mucosal margins. The obliteration of potential pleural spaces by good tube drainage, lung decortication, and the elective use of mechanical ventilation with positive end-expiratory pressure decreases the incidence of uncontrolled intrapleural sepsis.

Adult↗

Operant conditioning of fusional convergence ranges using random dot stereograms.

In Experiment 1, four 6- to 10-year-old strabismus patients, who had failed to improve convergence ranges using traditional vision training techniques, were given convergence training using random dot stereograms (RDS). An integral part of the RDS training procedure was the incorporation of an operant conditioning procedure providing for response-contingent positive reinforcement, immediate feedback, and preprogrammed systematic changes in convergence demand during discrimination learning. Findings indicated that operant RDS convergence training produced a significant increase in convergence ranges which transferred readily to vectogram tasks and resulted in a change from exotropia to exophoria for at least one patient. In Experiment 2, it was shown that improved convergence ability was a direct result of exposure to RDS of increasing convergence demand. It was concluded that young, uncooperative, language-deficient, or inattentive patients show improved convergence ranges when such training incorporates proper stimuli and the basic principles of learning and motivation into its training regimen.

Accommodation, Ocular↗