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Biomedical subjects

W Davis

Publications and source records attributed to W Davis.

At least 109 records · Page 6Linked to original sources
PubMed1986

Selection of replacement therapy for patients with severe factor VII deficiency.

The risk of significant bleeding in patients with severe Factor VII (FVII) deficiency is well documented. However, controversy regarding management exists not only for the choice of FVII replacement product, but also for the desired hemostatic level of FVII. Two case reports are presented where fresh frozen plasma (FFP) and several Factor IX (FIX) complex concentrates were used to achieve hemostasis. Significantly higher FVII levels were achieved with Proplex (FIX Complex, Hyland Therapeutics) than with other products. Although this and other reports indicate that minor bleeding can be controlled with levels of FVII under 15%, life-threatening hemorrhages require higher FVII levels that can be attained only by using a product with a significant FVII content. It is important to know the FVII content of FIX concentrates in order to plan appropriate therapy for patients with FVII deficiency.

Blood Coagulation Factors↗
PubMed1986

Functional electrical stimulation for the treatment of bilateral recurrent laryngeal nerve paralysis.

We have previously presented the concept of electrophysiologic pacing of bilaterally paralyzed vocal cord abductors as a solution to the difficult problem incurred in this clinical situation. Initially, we demonstrated that it was indeed feasible to electrophysiologically pace abduction of the vocal cords synchronously with respiration, employing the EMG activity of the diaphragm as a trigger stimulus. Further research has led us to evaluate other possible physiologic trigger stimuli to ascertain which of these will prove most suitable in long-term pacing studies. In this article, we will report our preliminary results, employing negative intrathoracic pressure occurring with respiration--as detected by an implanted pressure transducer as a trigger stimulus. This device was interfaced with a muscle stimulator attached to electrodes placed in the cricoarytenoid muscles in five canines whose recurrent laryngeal nerves had been sectioned bilaterally. In all animals, obvious physiologic synchrony of vocal cord abduction and a reduction of negative inspiratory intratracheal pressure was achieved during electrical pacing. This reinforces our initial findings that it is indeed feasible to pace vocal cord abduction in bilateral recurrent laryngeal nerve paralysis with resultant return of physiologic normality to the glottis. Thus, functional electrical stimulation offers an alternative approach to the difficult problems incurred in the patient with bilateral recurrent laryngeal nerve paralysis. It also demonstrates that physiologic negative intrathoracic pressure activity occurring with inspiration can be a trigger source.

Animals↗
PubMed1986

Variables which distinguish among classifications of exceptional children: learning disabled, emotionally disturbed, and educable mentally retarded.

The focus of this study was on children in public school classrooms who had been designated for special classes or as in need of special attention. It was the intent to take as many variables into account as possible relative to these children in order to determine significant associations among them. A discriminant analysis identified two functions which contributed to the separation of the criterion groups: LD, ED, EMR. Eight variables were found to significantly contribute to the discriminating power of the functions, classifying correctly 84% of the 62 cases.

Adolescent↗
PubMed1986

Comparison of diflunisal and acetaminophen with codeine in the treatment of initial or recurrent acute low back strain.

Effective pain relief and patient tolerance and acceptance are essential in outpatient management of mild to moderate pain of acute low back strain. This study evaluated the efficacy, tolerability, and acceptability of diflunisal and acetaminophen with codeine in patients with mild to moderate pain after an initial or recurrent acute low back strain. Both drugs demonstrated equipotent analgesic efficacy; however, diflunisal was superior to acetaminophen with codeine for patient tolerability and acceptability. The results demonstrated that the study drugs were effective in treating mild to moderate pain caused by acute low back strain in an ambulatory care setting.

Acetaminophen↗
PubMed1985

Electrophysiologic pacing of vocal cord abductors in bilateral recurrent laryngeal nerve paralysis.

We have reconfirmed our previous findings that controlled, reproducible, sustained, discrete vocal cord abduction can be achieved synchronously with respiration by electrophysiologic stimulation of the paralyzed posterior cricoarytenoid muscles. Moreover, we have demonstrated that this can be triggered synchronously by employing the normal physiologic chest wall movements that occur on respiration. To our knowledge, this represents the first report of functionally paced vocal fold abduction with respiration employing physiologic chest wall motions using an implantable device, and may represent an important step in the development of a physiologic approach to bilateral recurrent laryngeal nerve paralysis.

Animals↗
PubMed1985

Coordinated electrical pacing of vocal cord abductors in recurrent laryngeal nerve paralysis.

Electrodes were placed into the posterior cricoarytenoid and diaphragmatic muscles of five tracheostomized dogs. With the use of a sensor that would selectively detect diaphragmatic electromyographic activity, this activity served as a trigger and was amplified and interfaced with a muscle stimulator attached to electrodes placed in the posterior cricoarytenoid muscles. In all animals obvious physiologic synchrony of vocal fold abduction and a reduction of the negative inspiratory intratracheal pressure were observed during electrical pacing. This represents a preliminary step in the development of an alternative approach to the patient with bilateral recurrent laryngeal nerve paralysis.

Animals↗
PubMed1985

Tracheostomy tube fracture: an unusual etiology of upper respiratory airway obstruction.

Tracheostomy tube fracture with subsequent migration of the proximal fragment down the tracheobronchial tree is an almost unheard of cause of tracheal foreign bodies. Most such occurrences have been reported outside the United States, and only six previous reports have been filed. We report an additional case of fractured tracheostomy tube and review the literature.

Airway Obstruction↗
PubMed1984

Cimetidine, cigarette smoking, and recurrence of duodenal ulcer.

Three hundred seventy patients with recently healed duodenal ulcer entered into a one-year, double-blind, randomized multicenter trial comparing placebo with three different dose schedules of cimetidine (200 mg twice a day, 300 mg twice a day, and 400 mg at bedtime) for the prevention of recurrent duodenal ulcer. By the end of one year, the cumulative symptomatic recurrence rate as demonstrated by endoscopy was similar for the patients receiving the three dosages of cimetidine (19 per cent, 15 per cent, and 13 per cent, respectively; not significant), whereas the placebo-treated group had a 34.7 per cent symptomatic recurrence rate (P less than 0.01 as compared with each cimetidine group). Cigarette smoking was found to be an important variable; among the placebo recipients ulcer recurrence was significantly more likely in smokers (72 per cent) than in nonsmokers (21 per cent, P less than 0.001). The frequency of ulcer recurrence in smokers was significantly reduced by treatment with cimetidine (from 72 per cent to 34 per cent, P less than 0.). Smokers who received cimetidine were at least as likely to have a recurrence as were nonsmokers who received placebo (34 per cent vs. 21 per cent, not significant). Thus, smoking appears to be a major factor in recurrence of duodenal ulcer, and in smokers, giving up smoking may be more important in the prevention of ulcer recurrences than administration of cimetidine.

Cimetidine↗
PubMed1984

A comparison of the in-vitro antibacterial and complement activating effect of 'OpSite' and 'Tegaderm' dressings.

Two readily available semipermeable polyurethane dressings, 'OpSite' and 'Tegaderm', were tested for their in vitro ability to kill potential bacterial pathogens and activate complement C3. In bacterial killing tests, 'OpSite' was superior to 'Tegaderm' and in addition only 'OpSite' activated C3. It is concluded that in the practical situation, 'OpSite' could well confer a greater margin of safety.

Bacteria↗
PubMed1983

The effect of a clinical clerkship on attitudes of medical students toward anesthesiology.

The study on which this article is based evaluated the effect of a clerkship in anesthesiology on medical students' attitudes toward anesthesiology as a specialty, the role of anesthesiologists as physicians, career choice, and the usefulness of this experience in their learning. Eighty-four participating students filled out questionnaires on the first and the last day of a four-week clerkship. Responses to common questions in the questionnaires administered before and after the clerkship were compared by paired t-test to determine statistical significance. The results suggest that the clerkship (a) significantly improved graduating students' attitudes toward anesthesiologists as physicians and (b) provided a worthwhile clinical experience.

Anesthesiology↗
PubMed1983

Hemispheric asymmetry in the processing of Stroop stimuli: an altered format.

As in previous studies, the interference condition of the Stroop (color words printed in incongruent ink colors) was presented to male and female subjects. Unlike earlier studies in which word and color responses were elicited randomly, subjects knew in advance what to expect. Word responses were grouped together as were the color responses. Fifteen males and 15 females served in each of two conditions--word responses first or color responses first. In this altered format, an analysis of covariance revealed no gender or order of presentation differences in relation of word to color responses. When analyzed separately, there were no differences on the color responses but significantly shorter latencies for males on word responses. Word response latencies were shorter when presented before rather than after color responses for all subjects. The strong Stroop effect was ever present.

Adult↗
PubMed1982

Use of videotape in the preparation of children for cardiac catheterization.

To help children with congenital heart disease, and their parents, cope with the stress of hospitalization for cardiac catheterization, a videotape was developed entitled "Leonard Z. Lion Presents ... Learning About Your Heart Catheterization." Fifty-three patients with congenital heart disease, 3 to 12 years of age, were randomly assigned to experimental (N = 31) or control (N = 22) groups. Each viewed the catheterization videotape or an unrelated control videotape before cardiac catheterization. The child's knowledge, anxiety, and adjustment during and after hospitalization for catheterization were evaluated. The experimental group displayed a significantly greater knowledge of events and sensations experienced during hospitalization than controls (P less than .0001). Children in the experimental group tended to sleep more during the catheterization procedure (P = .05) and when awake to ask more questions (P = .02). After discharge, the experimental group also tended to demonstrate more independent behavior. We conclude that viewing this videotape on heart catheterization helped children with congenital heart disease to cope with the stress of hospitalization for the procedure.

Cardiac Catheterization↗
PubMed1981

Hemispheric asymmetry in the processing of Stroop stimuli: the effect of enhancement of spatial skills.

There is a body of evidence which supports the concept of biological determinants of hemispheric asymmetry. In addition, there appear to be environmental influences. the present investigation was designed to determine whether there are differences, on the Stroop phenomenon, between individuals with more developed spatial skills and controls, as well as between males and females. Thirty-six art students and 27 psychology students who had no training in drawing participated in this study. There were 25 males and 38 females, all of whom were right-handed. An analysis of covariance revealed that the covariable, the word, was significantly related to the color score for all groups. There was a significant difference between art students and controls and between males and females. Male art students had a significantly larger corrected color response mean than all other groups. There appears to be not only a significant statistical interaction but perhaps an interaction of biology with environment as well.

Art↗