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Biomedical subjects

W R Wilson

Publications and source records attributed to W R Wilson.

At least 307 records · Page 17Linked to original sources
PubMed1979

Cardiac valve replacement in congestive heart failure due to infective endocarditis.

From January 1961 to July 1974, 138 patients underwent cardiac valve replacement because of complications of infective endocarditis. The overall operative mortality was higher in patients with Class IV cardiac functional disability (17%) than in patients with Class III (7%) or II (8%). The mortality for patients who had undergone aortic valve replacement with Class IV disability was higher (22%) than that for patients with Class III (0) or II (6%). When compared with patients without infective endocarditis who had undergone cardiac valve replacement, the operative mortality per valve replacement was approximately the same when the degree of cardiac disability was the same at the time of surgery for both groups of patients. Patients with aortic regurgitant murmurs caused by infective endocarditis should be observed closely for the onset of heart failure, especially during the first month of disease. In patients with aortic or mitral incompetence, if heart failure develops or progresses during the first month, we believe that prompt cardiac valve replacement should be considered, because even heart failure that may initially appear mild often progresses to severe heart failure during this period.

Aortic Valve Insufficiency↗
PubMed1979

Linguistic experience and phonemic perception in infancy: a crosslinguistic study.

English- and Spanish-learning infants were tested for perception of 2 synthetic speech contrasts differing in voice onset time. The 2 pairs were chosen so that they were native to either Spanish or English. Using the Visually Reinforced Infant Speech Discrimination (VRISD) paradigm, 6--8-month-old infants were taught to respond to a change in auditory stimuli with a headturn. Correct headturns were reinforced by the activation of a lighted animated toy. While Spanish-learning infants provided evidence of discriminating both English and Spanish contrasts, English-learning infants only provided evidence of discriminating their native contrast. The results are discussed in terms of the role of linguistic experience in the development of speech perception skills in infancy.

Cross-Cultural Comparison↗
PubMed1978

Detection of syphilitic hearing loss.

Syphilis can cause sensorineural hearing loss that is potentially treatable. To determine the incidence of positive serological findings in patients with sensorineural hearing loss, the rapid plasma reagin card test (RPRCT) and the FTA-ABS test were performed in a study group composed of patients with sensorineural hearing loss of obscure origin. Of the 306 patients with sensorineural hearing loss, 20 (6.5%) demonstrated a positive FTA-ABS as compared with two of 100 (2%) of the control group. Considerable variation was found in the rate of the false-negative and the biological false-positive RPRCT as performed by our hospital and state laboratories when compared with the results of the FTA-ABS test. Syphilis should be considered in any patient with sensorineural hearing loss of obscure origin, despite a negative history for syphilis. The FTA-ABS is the preferred test to exclude hearing loss of syphilitic origin.

Adolescent↗
PubMed1978

Visual reinforcement audiometry (VRA) with young Down's syndrome children.

Visual Reinforcement Audiometry (VRA) was investigated with 41 Down's syndrome subjects between the ages of six months and six years. The VRA procedure involved monitoring a head-turn response to a complex noise signal presented in a sound field with an ascending presentation paradigm and reinforced by a complex visual reinforcer. Twenty-four of the infants and young children also were evaluated with the Bayley Scales of Infant Development (BSID) to allow for analysis of the efficacy of VRA as a function of developmental age. Results were as follows: (1) 28 (68%) of the infants and young children initially oriented towards the source of the auditory stimulus, (2) only a few of the subjects who did not initially orient could be taught to respond, (3) of the children who initially oriented or were taught to respond, thresholds were obtained on a large number (81%) in one visit, and (4) a systematic relationship was demonstrated between consistency of subject response using the VRA technique and BSID Mental Age Equivalent with 10 months being the critical age for determining the potential success of the procedure. In addition, the results implied a higher incidence of hearing loss in the Down's syndrome subjects than found in normal pediatric population.

Age Factors↗
PubMed1978

Anticoagulant therapy and central nervous system complications in patients with prosthetic valve endocarditis.

Among 52 cases of prosthetic valve endocarditis, adequate anticoagulant therapy was administered in 38 and discontinued or given in subtherapeutic dosage in 14. Our data suggest that anticoagulant therapy does not appreciably increase morbidity or mortality in patients with prosthetic valve endocarditis. On the contrary, in our patients the incidence of major clinical CNS (central nervous system) complications was increased and the mortality was higher if anticoagulant therapy was discontinued. CNS complications occurred in 10 of the 14 patients without adequate anticoagulant therapy and in three of the 38 with adequate anticoagulant therapy. Mortality was 57% among those treated without adequate anticoagulation and 47% among those with adequate anticoagulation. At autopsy, CNS complications were thought to be the primary cause of five of the eight deaths in cases without adequate anticoagulation.

Adolescent↗
PubMed1978

Short-term intramuscular therapy with procaine penicillin plus streptomycin for infective endocarditis due to viridans streptococci.

Thirty-three patients with viridans streptococcal infective endocarditis were treated for two weeks with intramuscular procaine pencillin, 1.2 million units every 6 hours, plus streptomycin, 500 mg intramuscularly every 12 hours. Nine patients (27%) had infections with relatively penicillin-resistant microorganisms (MIC greater than 0.1 microgram/ml or MBC greater than or equal 3.12 microgram/ml). Follow-up ranged from 2 months to 3.5 years. There were no relapses; Mild vestibular toxicity developed in one patient. One patient died two months after completion of antimicrobial therapy from sudden onset of severe congestive heart failure; Seven patients required cardiac valve replacement after completion of antimicrobial therapy. None died. We believe that this therapeutic regimen is effective antimicrobial therapy for infective endocarditis caused by viridans streptococci, irrespective of in vitro microbiologic data.

Adolescent↗
PubMed1978

Valve replacement in patients with active infective endocarditis.

Eleven of 138 patients with infective endocarditis (IE) who underwent cardiac valve replacement for IE during a 12 1/2-year period had active IE. Eight of the 11 (all with aortic IE) had positive blood cultures within 48 hours preoperatively; six of the eight had positive Gram stains and cultures of the excised cardiac tissue. All 11 patients had Class IV cardiac functional disability (New York Heart Association classification) at the time of surgery. Staphylococci (three patients with Staphylococcus aureus and one with S. epidermidis) were the most frequent isolates. Three patients died; two of these three deaths occurred in patients who had a sudden onset preoperatively of severe aortic regurgitation and heart failure. In one patient (S. epidermidis infection) prosthetic valve endocarditis developed. Cardiac valve replacement may be performed successfully in patients with active IE even when blood cultures are positive in the immediate perioperative period. The hemodynamic status of patients with IE should be the determining factor in the timing of cardiac valve replacement, rather than the activity of the infection or the length of preoperative antimicrobial therapy. A radical surgical procedure may be necessary in patients with myocardial or aortic abscesses in whom conventional aortic valve replacement is not possible.

Adolescent↗
PubMed1978

Cardiobacterium hominis endocarditis. Four cases with clinical and laboratory observations.

The clinical and microbiologic features of Cardiobacterium hominis endocarditis in four patients seen at the Mayo Clinic from 1971 through 1976 are described. All four were men ranging in age from 39 to 60 years. The precipitating factor in three was a dental procedure, and the illness was a prolonged, chronic one, with symptoms having been present 10 to 18 months before diagnosis. The other patient had a late prosthetic valve endocarditis and had had symptoms for only 3 months. Three patients were cured; the fourth died after 32 days of adequate therapy and what was considered a bacteriologic cure. Because of the pronounced fastidiousness of these bacteria, in vitro susceptibility tests could be done in only two of the four; the minimum inhibitory concentration for penicillin G was 0.07 microgram/ml in both. The therapeutic regimens were penicillin G plus streptomycin in the first case, predominantly penicillin G alone in the second, penicillin G for 2 weeks in the third, and ampicillin for 4 weeks in the fourth (prosthetic valve case) in addition to valve replacement. Clinical and laboratory experiences in the total reported cases lead us to believe that 3 weeks of therapy with penicillin G or ampicillin alone is adequate therapy for C. hominis endocarditis of natural valves.

Adult↗
PubMed1977

Control of headfly on sheep.

Headfly caused irritation to sheep in Northumberland from late June of each year 1973 to 1975. Numbers of headflies caught in sweep nets declined sharply from early August 1973 and 1975 but remained fairly high in 1974 until mid September. Attacks on sheep followed a similar pattern. The effectiveness of a number of fly repellent applications was examined. Headcaps gave good and sometimes complete protection.

Animals↗
PubMed1977

Visual reinforcement of head-turn responses in infants under 12 months of age.

The effect of complex visual reinforcement (animated toy animal) on auditory localization responses of infants below 12 months of age was studied. Sixty infants served as subjects and each subject received 30 presentations of complex noise at suprathreshold level. After each response to an auditory signal, one-half of the infants (experimental group) received complex visual reinforcement and the other half (control group) received no reinforcement. The experimental and control groups were further subdivided into three age groups: four months, five and six months, and seven to 11 months. Visual reinforcement produced significantly more responses (head turn) than no reinforcement for the two older age groups. There was no significant difference between the experimental and control conditions at four months of age.

Age Factors↗
PubMed1977

Developmental changes in speech discrimination in infants.

A visually reinforced infant speech discrimination (VRISD) paradigm is described and evaluated. Infants at two ages were tested with the new paradigm on the following speech contrasts: [sa] vs [va], [sa] vs [fa], [sa] VS [za], [as] vs [a:s], vs [a:z], [at] vs [a:d], [a:t] vs [a:d], [at] vs [a:t], [fa] vs [thetaa]and [fi] vs [thetai]. The data reported are compared with data on the same speech contrasts obtained from three month olds in a high-amplitude sucking paradigm. Evidence suggesting developmental changes in speech-sound discriminatory ability is reported. Results are interpreted in light of salience of available acoustic cues and in terms of new methodological advances.

Age Factors↗
PubMed1977

Abnormal chemotaxis in patients with cutaneous anergy.

Chemotaxis of polymorphonuclear leukocytes and mononuclear leukocytes was studied in six patients who had persistent cutaneous anergy. Four had previous infections (three fungal and one caused by Mycobacterium kansasii), one had sarcoidosis, and one had late-onset immunoglobulin deficiency. Our data indicate that some patients with persistent cutaneous anergy have a combined defect of leukocyte function. Lymphocytes incubated in vitro with mitogen failed to elaborate active lymphocyte-derived chemotactic factor when compared with controls. Polymorphonuclear leukocytes and mononuclear leukocytes responded poorly to normal chematactic factors compared with controls. The abnormal mononuclear leukocyte chemotaxis may play a role in the persistent cutaneous anergy of these patients.

Chemotaxis, Leukocyte↗
PubMed1977

Haemophilus endocarditis. Report of 14 patients.

From 1963 through December 1976, 14 patients with Haemophilus endocarditis were seen, 10 since January 1972. Four different species representing 15 isolates were cultured from the 14 patients: H. influenzae (1), H. aphrophilus (5), H. PARAPHROPHILUS (5), and H. parainfluenzae (4). One patient had infection with both H. aphrophilus and H. paraphrophilus. Minimal inhibitory concentrations of 12 of the tested 14 strains with ampicillin were 1.25 mug/ml or less. Tube dilution tests were not possible for minimal bactericidal concentrations (7 times) or serum bactericidal titers (5 times) of the 12 tested strains. The clinical picture varied from an insidious onset and mild uncomplicated disease to abrupt onset with severe multisystem disease. Twelve patients had murmurs on admission; congestive heart failure was absent in all 14 but embolization occurred in 6. Treatment periods of 3 to 7 weeks consisted of penicillin G or ampicillin plus aminoglycoside in nine patients and ampicillin alone in five. All 14 patients were cured; no relapses occurred. Value surgery was not needed for bacteriologic cure but was necessary 15 days after therapy in one patient and in four others from 12 to 22 months after therapy. We believe that ampicillin, 12 g/day alone for 3 weeks, is adequate treatment for Haemophilus endocarditis.

Adolescent↗