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Biomedical subjects

J C Cooper

Publications and source records attributed to J C Cooper.

At least 55 records · Page 3Linked to original sources
PubMed1991

Hearing in the elderly--the Framingham cohort, 1983-1985: Part II. Prevalence of central auditory processing disorders.

The relation between central auditory processing disorders (CAPD) and age has been described in selected subjects. However, the prevalence of CAPD in the general population has not been established. We tested 1026, 64- to 93-yr-old members of the Framingham Heart Study cohort with Central Institute for the Deaf W-22 lists (CID W-22) in quiet, the Synthetic Sentence Identification test with ipsilateral competing message (SSI-ICM), and the Staggered Spondaic Word test. The presence or absence of CAPD could be established with at least one of three indices in 1018 subjects. The CID W-22 performance-intensity function rollover index was greater than 0.20 in 1.4% of 1009 subjects. The difference between maximum CID W-22 and SSI-ICM (0 dB message-to-competition ratio) scores was greater than 20% in 18.2% of 816 subjects. The Staggered Spondaic Word category was moderately, severely, over-corrected moderately, or over-corrected severely abnormal in 10.7% of 941 subjects (using 12-59-yr-olds' norms and adjusting scores when appropriate). Abnormal results on any one index occurred in 22.6% of the subjects. Thus, we conclude that the prevalence of CAPD in the elderly is less common than previous studies would suggest. Furthermore, although the rate of CAPD increased with age, age accounted for no more than 15% of the variability of any of the three indices. Therefore, its presence is dominated by factors other than chronological age.

Age Factors↗
PubMed1991

Incidence of hearing decline in the elderly.

Pure-tone audiometry was done on 1475 persons on two occasions 6 years apart by the same audiologist in the same facility. The age of the subjects ranged from 58 to 88 years at the initial testing and 63 to 95 at the second. The average 6-year threshold change ranged from 1 to 8 dB at 250-6 kHz and 10-15 dB at 8 kHz. The differences in thresholds fell into two patterns, one for low frequencies (250-1 kHz) and the other for high frequencies (4-8 kHz). For the lows, thresholds worsened at an increasing rate with increasing age independent of the initial hearing level, and women's thresholds worsened more than men's. For the highs, the rate of threshold change decreased with age and with the initial threshold at rates that did not differ between genders. Using a change in PTA (0.5, 1, 2 kHz) of greater than 10 dB as a criterion, significant worsening occurred in the right ear in 8.5%, in the left ear in 13.5%, and in both ears of 4.1% of the subjects over the 6 year period. The rate of significant worsening increased with age. Although hearing loss increased with age, age alone accounted for less than 10% of the variance. Therefore, factors that co-vary with age may be responsible. The difference in phenomena between the low frequencies and the highs suggests that two different processes are occurring. Hair-cell degeneration is the most likely cause for the change in the high frequencies. Strial atrophy or other intracochlear processes may be the cause of the low frequency changes.

Age Factors↗
PubMed1991

The use of computed tomography in the evaluation of large multinodular goitres.

This study reports one unit's experience of the value of computed tomography (CT) in the evaluation of 24 patients with large cervical and retrosternal goitres. Of these patients, 17 were thought clinically to have symptoms of tracheal compression, but the CT demonstrated significant narrowing in only 12 cases. In the other five patients, surgery was deferred and other causes for their symptoms sought and treated. Seven patients were asymptomatic and CT failed to reveal any evidence of tracheal compression in six. In the remaining patient, however, CT revealed gross narrowing and urgent surgery was performed. When compared with CT, chest/thoracic inlet radiographs were misleading in 48% of patients, with tracheal narrowing being overestimated and underestimated. We conclude that CT gives useful information about tracheal compression in patients with large multinodular goitres, and is more accurate than chest/thoracic inlet radiographs.

Adult↗
PubMed1990

Hearing in the elderly: the Framingham cohort, 1983-1985. Part I. Basic audiometric test results.

Many studies have documented the decline in auditory function with age. We broaden that data base in this the first of a series of reports emanating from the auditory testing of the Framingham cohort during biennial exam 18. The results of the auditory questionnaire, hearing sensitivity, acoustic compliance measures, and word recognition tests obtained from 1662 men and women in their 60th through 90th decades are presented. Pure-tone thresholds increased with age but the rate of change with age did not differ by gender even though men had poorer threshold sensitivity. Maximum word recognition ability declined with age more rapidly in men than in women and was poorer in men than in women at all ages. Acoustic compliance and middle ear pressure did not vary with gender or age. Acoustic reflex thresholds to a contralateral stimulus at 1 kHz increased slightly with age, more in women than in men; ipsilateral acoustic reflex thresholds did not vary with age or gender. Hearing aids were being used in only 10% of subjects likely to benefit from amplification.

Acoustic Impedance Tests↗
PubMed1989

Chronic secretory otitis media: effects of surgical management.

To study the effectiveness of adenoidectomy and tympanostomy tubes in the treatment of chronic otitis media with effusion, we randomly assigned 578 4- to 8-year-old children to receive one of the following: bilateral myringotomy and no additional treatment (group 1), tympanostomy tubes (group 2), adenoidectomy and myringotomy (group 3), or adenoidectomy and tympanostomy tubes (group 4). The 491 who accepted surgical treatment were evaluated at 6-week intervals for up to 2 years. Treatment effect was assessed by four main outcomes: time with effusion, time with hearing loss, time to first recurrence of effusion, and number of surgical re-treatments. For the groups (in order), the mean percent of time with any effusion in either ear was 49, 35, 30, 26 (p less than .0001); the mean percent of time with hearing thresholds 20 dB or greater was 19, 10, 8, and 7 (p less than .0001) in the better ear; and 38, 30, 22 and 22 in the worse ear (p less than .0001); the median number of days to first recurrence was 54, 222, 92, and 240 (p less than .0001); and the number of surgical re-treatments was 66, 36, 17, and 17 (p less than .0001). The most notable adverse sequela, purulent otorrhea, occurred in 22%, 29%, 11%, and 24% of the patients assigned to groups 1 through 4, respectively (p less than .001). In severely affected children who have chronic otitis media with effusion resistant to medical therapy, adenoidectomy is an effective treatment. Adenoidectomy plus bilateral myringotomy lowered posttreatment morbidity more than tympanostomy tubes alone and to the same degree as did adenoidectomy and tympanostomy tubes. Adenoidectomy appears to modify the underlying pathophysiology of chronic otitis media with effusion. This effect is independent of the preoperative size of the adenoid. Tympanostomy tube drainage and ventilation of the middle ear provide adequate palliation so long as the tubes remain in place and functioning. We recommend that adenoidectomy be considered in the initial surgical management of 4- to 8-year-old children with hearing loss due to chronic secretory otitis media that is refractory to medical management and, further, that the size of the adenoid not be used as a criterion for adenoidectomy. Concomitant bilateral myringotomy with suction aspiration of the middle ear contents also should be done, with or without placement of tympanostomy tubes at the discretion of the surgeon.

Acoustic Impedance Tests↗
PubMed1989

High-frequency electrostimulation hearing after mastoidectomy.

This study was undertaken to measure the degree of high-frequency sensorineural hearing loss following mastoid surgery. Twenty-five patients undergoing mastoidectomy procedures were tested preoperatively, less than 2 days postoperatively, and at 30 days postoperatively using the Tonndorf Audimax 500 high-frequency audiometer. Electrostimulation thresholds in 1-kHz intervals, from 1 to 20 kHz, were measured, and the highest detectable frequency was determined to within 0.1 kHz. Surgical drilling time was recorded. Average drilling time was 51 minutes. A significant temporary threshold shift was observed, measurable at multiple frequencies, less than 48 hours after mastoidectomy. There was no clinically significant change in electrostimulation thresholds (measured in 1-kHz increments, from 1 to 16 kHz) preoperatively to 30 days postoperatively. A statistically significant average loss of 0.89 kHz in the highest frequency producing a measurable response was noted (p less than 0.05). Determinations of the highest measurable frequency may be the most sensitive measure of surgically-induced, high-frequency sensorineural hearing changes.

Adolescent↗
PubMed1988

The nature of biosensor technology.

The biosensor exploits the unique specificity of biological recognition events by coupling an enzyme, antibody or other biorecognition species to a transducing device. Interaction of the biocomponent with substrate or antigen is thus converted into a suitable quantitative output. The development of these biosensors is a multidisciplinary effort, exploiting many of the emerging semiconductor and optics technologies and integrating many traditional assay techniques. The impact of these biosensors is likely to be wide-ranging, with applications in medical and industrial environments as well as a variety of other fields.

Biological Assay↗
PubMed1988

Review of the environmental toxicity of quaternary ammonium halides.

This paper summarizes all available information on the environmental toxicity of quaternary ammonium compounds (QACs). Ten-minute contact kills of bacteria occur at 50-333 mg/liter. These chemicals are acutely toxic at approximately 1 mg/liter to invertebrates and fish and toxicity is occasionally as low as 0.1 mg/liter; no-effect levels are generally 10 times lower than LC50 values. Toxicity to invertebrates and fish appears to be relatively independent of structure; the compounds studied, which have a large variety of structures, are all toxic at approximately the same order of magnitude. The QACs tested inhibited plant growth at 3-5 mg/liter. Predictions of toxicity to QACs are made based on knowledge of structure-activity relationships.

Animals↗
PubMed1988

Product line cost estimation: a standard cost approach.

Product line managers often must make decisions based on inaccurate cost information. A method is needed to determine costs more accurately. By using a standard costing model, product line managers can better estimate the cost of intermediate and end products, and hence better estimate the costs of the product line.

Accounting↗
PubMed1988

Principles and methods of managerial cost-accounting systems.

An introduction to cost-accounting systems for pharmacy managers is provided; terms are defined and examples of specific applications are given. Cost-accounting systems determine, record, and report the resources consumed in providing services. An effective cost-accounting system must provide the information needed for both internal and external reports. In accounting terms, cost is the value given up to secure an asset. In determining how volumes of activity affect costs, fixed costs and variable costs are calculated; applications include pricing strategies, cost determinations, and break-even analysis. Also discussed are the concepts of direct and indirect costs, opportunity costs, and incremental and sunk costs. For most pharmacy department services, process costing, an accounting of intermediate outputs and homogeneous units, is used; in determining the full cost of providing a product or service (e.g., patient stay), job-order costing is used. Development of work-performance standards is necessary for monitoring productivity and determining product costs. In allocating pharmacy department costs, a ratio of costs to charges can be used; this method is convenient, but microcosting (specific identification of the costs of products) is more accurate. Pharmacy managers can use cost-accounting systems to evaluate the pharmacy's strategies, policies, and services and to improve budgets and reports.

Accounting↗
PubMed1987

Effectiveness of adenoidectomy and tympanostomy tubes in the treatment of chronic otitis media with effusion.

To study the effectiveness of adenoidectomy and of the placement of tympanostomy tubes in the treatment of chronic otitis media with effusion, we randomly assigned 578 children, aged four through eight years, to receive bilateral myringotomy and no additional treatment (Group 1), placement of tympanostomy tubes (Group 2), adenoidectomy (Group 3), or adenoidectomy and placement of tympanostomy tubes (Group 4). The 491 children who underwent one of these treatments were examined at six-week intervals for up to two years. The mean time spent with effusion of any type in either ear over the two-year follow-up in the four groups was 51, 36, 31, and 27 weeks, respectively (P less than 0.0001), comparing Group 1 with each of the other groups. Hearing was equivalent in Groups 2, 3, and 4, and was significantly better than in Group 1. The most frequent sequela, purulent otorrhea, occurred one or more times in 22, 29, 11, and 24 percent of the subjects in Groups 1, 2, 3, and 4, respectively (P less than 0.001). Adenoidectomy plus bilateral myringotomy lowered the overall post-treatment morbidity (as measured by hearing acuity in the most severely affected ear [P = 0.0174] and the number of surgical retreatments required [P = 0.009]) more than did tympanostomy tubes alone and to the same degree as did adenoidectomy and tympanostomy tubes. We conclude that adenoidectomy should be considered when surgical therapy is indicated in children four to eight years old who are severely affected by chronic otitis media with effusion.

Adenoidectomy↗
PubMed1987

Recovery from outpatient anaesthesia: a comparison of incremental propofol and propofol-isoflurane.

Propofol was used to induce anaesthesia in 60 patients undergoing minor outpatient gynaecological procedures. Maintenance was with 66% nitrous oxide in oxygen, plus either isoflurane or 10-mg increments of propofol. Recovery was assessed using both clinical and psychomotor criteria and the results compared with those obtained in a non-anaesthetized control group. As far as the two test groups were concerned, initial recovery was more rapid in the incremental propofol group but, by 1 h after surgery, there were no differences between all three groups.

Adolescent↗
PubMed1986

Effects of a long-acting somatostatin analogue in patients with severe ileostomy diarrhoea.

Proctocolectomy (PC) with small bowel resection may lead to profuse ileostomy diarrhoea which can be difficult to treat. The effect of a recently developed long acting somatostatin analogue (SMS 201-995) on ileostomy output was investigated in 5 patients who had undergone PC and ileal resection (median 120 cm) and who suffered severe diarrhoea (4-7 litres/24 h). Gastric emptying, transit of a standard meal through the small bowel and the amounts of nutrients excreted were simultaneously determined during double blind infusion of SMS (25 micrograms/h) and placebo (isotonic saline 125 ml/h). SMS 201-995 significantly reduced ileostomy output (P less than 0.05) and water excretion (P less than 0.05) and prolonged small bowel transit time (P less than 0.05). Whilst having little effect on gastric emptying, or on the excretion of glucose or nitrogen, fat excretion was significantly increased (P less than 0.05). In two patients subcutaneous administration of SMS 201-995 (50 micrograms b.d.) has maintained a reduced ileostomy output for 4 and 6 months respectively.

Body Water↗
PubMed1986

Body composition in ileostomy patients with and without ileal resection.

Body composition was measured in 24 patients who had previously undergone proctocolectomy and ileostomy. One group (control group) had undergone resection of only small amounts of terminal ileum (median 4 cm), the other group of patients (resected group) had undergone resection of greater lengths of small bowel (median 54 cm). These values of body composition were then compared with predicted values in normal subjects. Proctocolectomy and ileostomy without ileal resection did not significantly affect body weight, or the body contents of fat or water, but led to a reduction in total body nitrogen and total body potassium, suggesting a reduction in fat free mass. A modest resection of the terminal ileum undertaken during the course of proctocolectomy decreased body weight largely because of a reduction in body fat. None of the ileostomy patients was found to be dehydrated.

Adult↗
PubMed1986

Outcome of colectomy and ileorectal anastomosis in Crohn's disease.

The outcome of 42 patients undergoing colectomy and ileorectal anastomosis (IRA) for Crohn's colitis, which largely spared the rectum, was studied. Operative mortality was 7% (3 patients) and each patient died as a result of anastomotic breakdown. The overall incidence of anastomotic breakdown was 16.7% (7 patients). This complication was higher following a primary anastomosis (6 of 26 patients: 23%), compared with a delayed anastomosis (1 of 16 patients: 6.3%). Patients were followed up for a median of 7 years (range 3 months-20 years) and questioned with regard to their quality of life. Cumulative reoperation rates at 5 years were 55%, and at 10 years were 74%. Most patients assessed following surgery enjoyed an unrestricted social life and none would contemplate the alternative of an ileostomy. The study suggests that despite the high incidence of recurrence, the quality of life following surgery can be good and supports the view that colectomy and ileorectal anastomosis can be used as an alternative to proctocolectomy in the treatment of Crohn's colitis for a select group of patients.

Colectomy↗