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Biomedical subjects

A M Cook

Publications and source records attributed to A M Cook.

At least 127 records · Page 7Linked to original sources
PubMed1968

Microbial contamination on disposable hypodermic syringes prior to sterilization by ionizing radiation.

A large number of syringes were taken from the production lines of three independent manufacturers; the numbers and types of microorganisms contaminating these randomly sampled syringes were assessed in the laboratories maintained by each of these manufacturers for routine sterility testing, according to a standard protocol devised by the Research Committee of the UK Panel on Gamma and Electron Irradiation, which coordinated the investigation and analyzed the results. Items produced by a manufacturer were assessed for microbiological contamination both in their own laboratories and in the laboratories of the other manufacturers. The level of "false-positive" results was determined independently for each laboratory by the testing of "known sterile" items which had been subjected to the radiation-sterilization process. Both the percentage of syringes initially sterile and the average number of organisms per contaminated syringe differed among the three manufacturers. When corrected for interlaboratory differences, the number of syringes initially sterile ranged from 16 to 48%, and the mean number of organisms per contaminated syringe was 20 to 70. Of 964 syringes tested by all three laboratories, only one contained over 1,000 aerobic organisms (1,133). The most common organisms found were coagulase-negative, gram-positive cocci. Two manufacturers assessed contamination by anaerobic organisms; of 610 syringes, 1 contained 4,275 organisms and 3 more had 100 to 1,000 organisms, but 488 (80%) were uncontaminated by anaerobes. The results are discussed in the context of the choice of radiation dose necessary for the sterilization of medical products manufactured under controlled hygienic conditions.

Bacteria↗
PubMedDate not supplied

The filterability of leukocytes in undiluted blood.

A filtrometer is described for measuring the flow of fluids through microfilters. The flow of Newtonian fluids through the filters can be predicted from the diameter, length and number of pores. There are no physical artefacts such as turbulent flow or a significant lag period before steady-state flow is achieved. The instrument has been used as a viscometer and has been used to record and analyse the flow of undiluted blood through 5 microns polycarbonate filters. The calculated viscosity of Newtonian fluids agrees well with those measured by a more conventional viscometer (Ostwald). Flow profiles of blood have been analysed to give both the numbers and the flow properties of a small population of slow leukocytes which equate numerically with the monocytes. They are subdivided into three distinct sub-populations, according to their rheological properties, and these are termed SL1, SL2 and PB. The concentration of these cells, in blood, are 0.12 +/- 0.02 x 10(6) ml-1, 0.11 +/- 0.02 x 10(6) ml-1, 0.09 +/- 0.02 x 10(6) ml-1 in young females aged about 25 years. The transit time of these cells, through 5 microns pores, is 34.8 +/- 1.4 s, 147.5 +/- 2.5 s and > 300 s, respectively. Analysis of blood from older men (53-79 years) gives essentially the same results although the concentration of SL1 is slightly higher at 0.19 +/- 0.09 x 10(6) ml-1.

Adult↗
PubMedDate not supplied

Treatment of chronic iliac artery occlusions by means of percutaneous endovascular stent placement.

PURPOSE: A retrospective evaluation of outcomes in patients with chronic iliac occlusions treated with insertion of metallic endovascular stents, without previous thrombolysis, on an intention-to-treat basis. MATERIALS AND METHODS: Seventy-two patients with chronic iliac occlusion underwent attempted stent placement from either the ipsilateral or contralateral femoral artery. There were 49 men and 23 women. Mean age was 63.1 years (range, 39-88 years). A total of 89 stents were deployed in 67 patients. Follow-up was from 24 to 69 months (mean, 37.5 months). RESULTS: Stents were successfully deployed in 67 patients (93%), with two early failures, giving a primary success rate of 90%. There were five significant and four insignificant procedural complications. There were four late failures (all within the first year) and four non-stent-related deaths. CONCLUSION: Endovascular stent placement offers an alternative to surgery in the treatment of chronic iliac occlusions.

Arterial Occlusive Diseases↗
PubMedDate not supplied

Cost effective clinical engineering internships in community hospitals.

A cooperative Clinical Engineering Internship Program has been developed jointly by California State University, Sacramento, and Sutter Community Hospital of Sacramento, California. The program, in existence since 1972, was developed and continues to operate on a cost-effective basis. The hospital has benefitted through the utilization of skilled professional personnel (interns), and the university has benefitted from the availability of a clinical engineering "laboratory" for experiential training.

Biomedical Engineering↗
PubMedDate not supplied

Skills required for clinical engineering practice: results of a survey.

In order to provide information to individuals conducting or planning educational programs in clinical engineering, a survey of skills required for practice in this field was carried out. A total of 127 responses from university-based (44) and practicing (83) clinical engineers were received. The results were tabulated separately for these two groups. The survey form was divided into two parts: basic skills and clinical engineering skills. The responses indicated an emphasis on medical instrumentation, basic life science (physiology and anatomy) information, and organizational and quipment control skills.

Biomedical Engineering↗
PubMedDate not supplied

Different therapeutic approaches and outcome in the treatment of pterygium.

PURPOSE: This study was initiated to investigate the role of different therapeutic modalities in the outcome of the surgical treatment of pterygium. METHODS: The results of treatment of pterygia with a variety of surgical techniques were studied in 56 eyes (49 patients) operated on at Bristol Eye Hospital during a period of five years. The surgical techniques included simple excision; bare sclera; conjunctival autograft; sliding conjunctival flap; lamellar keratoplasty and penetrating keratoplasty. Twelve eyes received additional beta irradiation in a fractionated total dose of 40 Gys. RESULTS: The incidence of recurrence was 23.2% for the 43 treated primary pterygia, and 23% for the 13 recurrent pterygia. All recurrences occurred between 2.5 and 11 months postoperatively. None of the 11 cases where additional beta irradiation was used showed any recurrence or other complication within the study period. In the recurrent pterygia group, the cases treated with a combination of surgical excision and beta irradiation, showed significantly lower recurrence rate (p < 0.001) compared to those cases treated with surgical excision alone. CONCLUSIONS: Beta irradiation as a complement to surgical treatment of pterygium, is successful in treating high risk cases such as reoperations, whereas for the majority of primary pterygia surgical excision alone is adequate. Additionally, follow up of one year will reveal any recurrences.

Adolescent↗