Biomedical subjects

M Lewis

Publications and source records attributed to M Lewis.

716 records · Page 40Linked to original sources

PubMedDate not supplied

Increased oxygen pressure to improve the efficiency of membrane oxygenators.

Increased O2 pressure was used in a specially constructed oxygenator to test the concept of improved oxygen transfer with hyperbaria. Three membranes were tested: 5-mil Silastic, 1-mil copolymer, and 0.5-mil Teflon. Results are analyzed in terms of pressure, venous saturation, and flow. The 5-mil Silastic proved to be the most reliable and efficient at all levels of saturation and pressure. Oxygen transfers up to 100 cc/m2/min were recorded at lower venous saturations. Normal pCO2 differentials were maintained at atmospheric pressure but decreased as pressure increased. For the Silastic and copolymer membranes, peak efficiency for O2 transfer was at oxygen pressure 3 lb/in2, or 140 mmHg. This usually required a blood pressure of over 300 mmHg using an average blood layer of 0.5 mm. Changes of pressure were more critical than flow, although O2 transfer was found to increase up to flows of 1200 cc/min/m2. Pressure levels of 0-30 lb/in2 were tested. Teflon was most efficient at pressures of 10-15 lb/in2, and did not transfer CO2 in detectable amounts at these pressure levels. Plasma hemoglobin, WBC, and platelets were not seriously altered when studied over 4-hour periods at constant pressures.

Animals↗

PubMedDate not supplied

Lifelong learning. Why professionals must have the desire for and the capacity to continue learning throughout life.

This paper will outline the theoretical constructs pertaining to lifelong learning, adult education, continuing professional development and the learning society. The need for all professionals to have highly developed learning skills in a society racing with change is evident. Pressures placed on health information managers to continue their learning beyond graduation are many and varied. Continuing professional education is one avenue that enables health information managers to continue their learning beyond graduation. Attributes of a typical lifelong learner are included in this paper to enable readers to self-assess their capacity for continued learning and their desire to undertake it. The paper concludes with a list of strategies for learners to enhance their lifelong learning skills. The role that educators can play in developing lifelong learning competence in students and graduates is also outlined.

Adult↗

PubMedDate not supplied

Method for qualifying microbial removal performance of 0.1 micron rated filters. Part III: bacterial challenge tests on 0.2/0.22 and 0.1 micron rated filter cartridges with Hydrogenophaga (formerly Pseudomonas) pseudoflava.

We have previously reported on the preliminary characterization of Hydrogenophaga (formerly Pseudomonas) pseudoflava for potential use as a standard challenge organism to qualify 0.1 microm rated filters. This article reports on the retention efficiencies of a large panel of 0.2/0.22 microm and 0.1 microm rated filter cartridges for H. pseudoflava (ATCC 700892) versus the retention capabilities of the same filters for Brevundimonas diminuta (ATCC 19146). A total of thirty-two 0.2/0.22 microm rated filter cartridges, spanning nine different "sterilizing grade" filter types from four different filter manufacturers, were challenged with H. pseudoflava at challenge levels exceeding 10(7) cfu/cm2. H. pseudoflava was shown to penetrate every 0.2/0.22 microm rated filter tested, with log titer reduction (LTR) values ranging from 3.5 to 7.7 logs. H. pseudoflava was shown to be more penetrative than B. diminuta under the same challenge conditions. B. diminuta was fully retained by nineteen of the twenty 0.2/0.22 microm rated filters that were challenged with both organisms. In the case of 0.1 microm rated filters, eighteen filter cartridges, spanning five different filter types from three manufacturers were tested. H. pseudoflava was consistently retained by four out of the five filter types tested, with LTR values in excess of 11.5 to 12.2 logs. The 0.1 microm rated filter type that was penetrated by H. pseudoflava has been previously demonstrated to be not fully retentive for naturally occurring bacteria. The data show that H. pseudoflava penetrates 0.2/0.22 microm rated filters just as readily as B. diminuta penetrates 0.45 microm rated filters. In addition, titer reductions provided by 0.2/0.22 microm rated filters for H. pseudoflava are comparable to those reported for A. laidlawii mycoplasma, albeit under different conditions. This study demonstrates that H. pseudoflava meets all criteria for use as a standard organism for qualifying the microbial removal performance of 0.1 microm rated filters for enhanced sterility assurance.

Acholeplasma↗

PubMedDate not supplied

CT of muscle necrosis following radiation therapy in a patient with head and neck malignancy.

Radiation-induced changes within skeletal muscle may be seen on follow-up CT or MR scans in patients who have undergone postoperative radiation therapy for head and neck tumors. Because they may mimic recurrent disease, these changes should be borne in mind.

Aged↗

PubMedDate not supplied

General practice (family medicine): meeting the health care needs of Nepal and enriching the medical education of undergraduates.

Explore the source record for details and available documents.

Adult↗

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Individually specified drug immunoconjugates in cancer treatment.

Forty-three patients with disseminated refractory malignancies each received an individually-specified combination of either Adriamycin (24 patients) or mitomycin-C (19 patients) conjugated murine monoclonal antibodies. Tumors were typed using a panel of antibodies with both immunohistochemistry and flow cytometry. Cocktails of up to six antibodies were selected based on binding greater than 80% of the malignant cells in the biopsy specimen. These monoclonal antibody cocktails were drug conjugated and administered intravenously. Seventeen out of twenty-four patients had reactions to the administration of Adriamycin immunoconjugates, but these were tolerable in all but two patients. Fever, chills, pruritus and skin rash were by far the most common transitory reactions. All were well controlled with premedication. In several patients it was demonstrated that there was limited antigenic drift among various biopsies within the same patient over time. Up to 1 gram of Adriamycin and up to 5 grams of monoclonal antibody were administered. The limiting factor appeared to be a variable dissociation of active Adriamycin from the antibody which unpredictably caused hemopoietic depression. Similar findings were noted in 19 patients with mitomycin-C conjugates. Thrombocytopenia at a 60mg dose of mitomycin-C in this schedule was dose limiting. Preliminary serological evidence suggests that the development of an IgM antibody which is specific against the mouse monoclonal antibody has the specificity and sensitivity to predict clinical reactions. These antibodies were quantitatively less in mitomycin-C patients. Selected patients were re-treated. One patient with chronic lymphocytic leukemia had re-treatment on three occasions and demonstrated regression of peripheral lymph nodes. Two patients with breast carcinoma had definite improvement in ulcerating skin lesions and two patients with tongue carcinoma had shrinkage of their lesions. No responses were seen with mitomycin-C conjugates but binding was noted to tumors and colon with likely drug induced colitis seen after colon binding. This study demonstrates the feasibility and illustrates technical considerations in preparing drug immunoconjugate cocktails for patients with refractory malignancies. Cocktail formulation and antibody delivery was accomplished. The major technical hurdle appears to be the selection of effective conjugation methods that can be used to optimally bind drugs to monoclonal antibodies for targeted cancer therapy.

Animals↗

PubMedDate not supplied

Blood groups in Newfoundlanders.

Data are presented on 30 high and low incidence antigens and on the distribution of the alleles of 14 blood group systems in a random sample of Newfoundlanders. The distribution of alleles in Newfoundland was compared to founder populations where possible and to the Canadian Caucasian population in general; no significant differences were found. Six rare alleles were observed (IN*a, NFLD, TAR, RH*x, RH*w, RH*V) in a population of 234 individuals. A high incidence of rare alleles has been reported in other isolate populations.

Alleles↗

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