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Biomedical subjects

E C Lee

Publications and source records attributed to E C Lee.

At least 73 records · Page 4Linked to original sources
PubMed1984

Functional responses of tumor cells to phorbol esters: role for prostaglandins.

The effects of phorbol esters on five murine cell lines were examined. In three of these lines, all of which were highly malignant, phorbol ester treatment induced motility and foreign surface adherence while concomitantly inhibiting proliferation. In two other, nonmalignant cell lines phorbol ester treatment stimulated proliferation but did not influence motility or adherence. Possible roles for prostaglandins in these responses were investigated. The mitogenic effects of the phorbol esters were duplicated by prostaglandin F2 alpha. In contrast, prostaglandin E1 and prostacyclin inhibited proliferation induced by the phorbol esters. These agents also inhibited phorbol ester-induced cell motility.

6-Ketoprostaglandin F1 alpha↗
PubMed1984

Stimulation of murine tumour cell motility by laminin.

Several variant cell lines that are deficient in surface laminin have been isolated from heterogeneous murine tumour populations. The parent populations from which these variant lines were isolated contain cells that express high levels of surface laminin as indicated by immunofluorescence, immunoperoxidase/electron microscopy and immunoprecipitation. The laminin-deficient lines were compared with their respective parent populations for motility by both the Boyden Chamber assay and the agarose assay. In both assays, the laminin-positive populations were much more motile than the laminin-deficient lines. The addition of exogenous laminin to the laminin-deficient lines significantly increased their motility. These observations are of interest since cell motility is thought to contribute to tumour cell metastasis, and the laminin-positive cell populations are highly tumorigenic and metastatic, while the laminin-deficient cells are of low tumorigenicity and are virtually non-metastatic.

Animals↗
PubMed1984

Protein degradation following treatment with hydrogen peroxide.

Pretreatment of hemoglobin with 50-5000 nmol hydrogen peroxide (H2O2) increased its susceptibility to proteolysis by a number of purified enzymes, including trypsin, chymotrypsin, elastase, and plasmin, and by the neutral protease of rat peritoneal leukocytes. Pretreatment of the protein substrate with catalase-inactivated H2O2 had no effect. Separation of the proteolytic fragments by G-75 Sephadex gel filtration indicated no apparent differences in the size distribution of the fragments produced by treatment with the H2O2/proteolytic enzyme combination as compared with enzyme treatment alone. A partially purified preparation of rat glomerular basement membrane was also treated with proteolytic enzyme alone or in combination with H2O2. As with the hemoglobin, pretreatment of the glomerular basement membrane with H2O2 increased its susceptibility to subsequent proteolytic attack. In addition, treatment of a basement membrane glycoprotein, fibronectin, with H2O2 also increased its sensitivity to subsequent proteolysis. These results suggest that in addition to their other proinflammatory activities, oxygen-derived metabolites may contribute to tissue destruction by altering the susceptibility of proteins to hydrolytic enzymes.

Animals↗
PubMed1984

A computer-managed clinical evaluation system: implications for competency-based dietetic education programs.

Instruments for evaluating clinical performance of students were developed, tested, and designed for a computer-managed evaluation system for the competency-based dietetic internship program at Emory University, Atlanta. The development, evaluation, and utilization of the instruments are described. The method of development included: (a) analysis of validated competencies and performance criteria to determine aspects of behavior appropriate to measure in clinical settings, (b) specification of major areas to be evaluated, (c) specification of component behaviors within each of the major areas, (d) specification of criteria to be used in evaluating component behaviors, and (e) definition of the rating continuum. Validation of the instruments consisted of determinations of content validity, interrater reliability, and practicality. Results of the use of the computer-managed evaluation system indicated that the instruments were valid, reliable, and practical to use for evaluating students' clinical performance.

Computers↗
PubMed1984

Burkitt's lymphoma in AIDS: cytogenetic study.

Cytogenetic studies were done in two cases of Burkitt's lymphoma in homosexual individuals with possible acquired immune deficiency syndrome (AIDS). The chromosomal abnormalities found are consistent with those previously described in the nonendemic form of Burkitt's lymphoma, with one of the two patients having the variant translocation, t(8;22). The production of the kappa light chain immunoglobulin by the tumor cells from the patient having t(8;22) and the occurrence of the different sites of translocation of the duplication of 1 q in the second patient are unusual findings. Whether there is an increase in the incidence of the variant translocation t(8;22) is yet to be determined.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Colonoscopic polypectomy in a regional teaching hospital.

Five hundred and thirty-five polyps were found in 200 patients over 6 years at a regional teaching hospital. Eighty-five per cent of the patients were from the hospital area yet the presentation of the patients, the complications of polypectomy, the size, distribution and histological features of the polyps were similar to large series reported from metropolitan specialist centres of referral both in this country and the USA. However, a smaller proportion of our polyps were over 1 cm diameter. Between 25 and 53 per cent of patients had recurrent or residual polyps on the second and third colonoscopy. Patients with two or more polyps at the first endoscopy were significantly more likely (P less than 0.01) to have further polyps at follow-up. We therefore recommend that patients with colonic polyps are colonoscoped annually until free from polyps for 2 years, before being placed on colonoscopic review at 5-year intervals.

Colon↗
PubMed1983

Split ileostomy and ileocolostomy for Crohn's disease of the colon and ulcerative colitis: a 20 year survey.

The clinical course of 140 patients who have had a split ileostomy for ulcerative colitis or colonic Crohn's disease over a 20 year period is reported. In 37 patients with ulcerative colitis there was no sustained improvement. In the 102 patients with Crohn's disease there was an immediate clinical improvement in 95, which was sustained in 65. Thirty patients have subsequently required a proctocolectomy for persistent inflammation, and 28 are still defunctioned. Bowel continuity was restored after 61 split ileostomies and in 44 patients intestinal continuity remains intact at the present time (mean follow up since closure = 62.5 months, range 0-231 months). It is concluded that a split ileostomy is a safe conservative operation producing at least temporary improvement in severely ill and malnourished patients with Crohn's colitis, and that if a subsequent resection becomes necessary it may be less extensive than was thought applicable at the initial operation. In 27 patients a resection has not been required.

Adolescent↗
PubMed1983

Cytogenetic studies of human breast cancer lines: MCF-7 and derived variant sublines.

Cytogenetic studies of the human breast cancer cell line MCF-7 and the sublines derived from it demonstrated extensive aneuploidy with both numerical and structural abnormalities and a wide range of heteroploidy. Detailed G-banding analyses showed that loss of marker chromosomes was a rare event, while formation of additional structural abnormalities was very common in these long-term cultures. All chromosomes were involved in these abnormalities. Loss of a morphologically normal X-chromosome may be related to the loss of estrogen receptors in these cell lines. With the exception of one subline, all cell lines had a short homogeneously staining region (HSR) on chromosome 7. Although the parent MCF-7 line had tetrahydrofolate dehydrogenase levels within the normal range, a lengthened HSR has been found in MCF-7 lines that are resistant to methotrexate. This observation strongly favors the association of an increased level of tetrahydrofolate dehydrogenase with HSR. In conclusion, the inherent genetic instability in this group of related cell lines may explain the heterogeneity found in this tumor. Continuous chromosomal rearrangements and numerical changes may reflect an ongoing process of selection and adaptation in these cell lines established from a breast carcinoma and may be characteristic of the aggressiveness of this neoplasm.

Aneuploidy↗
PubMed1982

Specific chromosome defect associated with human small-cell lung cancer; deletion 3p(14-23).

A specific, acquired chromosomal abnormality (deletion 3p) has been found in at least one chromosome 3 in 100 percent of the metaphases in 12 of 12 cell lines cultured from human small-cell lung cancer tissue and in 2-day tumor culture specimens from three patients. Analysis of the shortest region of overlap shows the deletion to be 3p(14-23). This specific change was not seen in five of five lung cancer cell lines other than small-cell lung cancer or in two lymphoblastoid lines cultured from cells of small-cell lung cancer patients whose tumors had the 3p deletion.

Carcinoma, Small Cell↗
PubMed1982

The effect of split ileostomy on perianal Crohn's disease.

The effect of 32 split ileostomies on 29 patients with severe symptomatic perianal Crohn's disease is reported. The perianal disease improved or healed after 23 (72 per cent) split ileostomies, although it relapsed in 2 patients while diverted and in 6 after closure of split ileostomy. Seven of 12 rectovaginal fistulas healed initially but only remained healed in those patients without rectal involvement with disease. At the time of review 6 patients have normal bowel continuity, 8 have had proctocolectomies and 15 are still defunctioned. Split ileostomy should be considered as an initial step in the management of intractable perianal disease.

Adolescent↗
PubMed1982

Factors affecting survival of Pseudomonas cepacia in decongestant nasal sprays containing thimerosal as preservative.

Strains of Pseudomonas cepacia, isolated from packages of nasal spray preserved with thimerosal, showed a high degree of resistance to the organomercurial, as compared to low and moderate resistance of standard laboratory strains or isolates from water. The product isolates were shown to degrade the thimerosal to metallic mercury which volatilized from the product or assay medium. The addition of organic nutrient was essential for survival of unadapted cells in the product. However, when cells were first grown in diluted product containing added nutrient and then inoculated into the full-strength product, survival and growth occurred even in the absence of added nutrient. The time required for growth to occur was inversely related to the amount of added nutrient. At low nutrient concentrations, approximately 99.9% of the inoculated cells were killed rapidly, but after a lag time of 7-12 days, the few survivors began to increase in numbers and eventually attained high cell concentrations. These findings should be useful in planning production and testing programs with thimerosal-preserved products.

Aerosols↗
PubMed1982

A nonrandom chromosomal abnormality, del 3p(14-23), in human small cell lung cancer (SCLC).

In order to determine whether or not there are specific chromosomal changes in small cell lung cancer (SCLC), karyotypic analyses of 16 continuous SCLC tissue culture lines, three fresh tumor specimens (bone marrow), one direct preparation of bone marrow involved with SCLC, and two lymphoblastoid lines derived from SCLC patients were studied. Cell lines were derived from primary tumor, or metastases to bone marrow, subcutaneous nodules, or pleural fluid; all 16 lines had biochemical and histologic properties characteristic of SCLC. Of the 15 males and 3 females, 6 patients had no prior treatment. All of the 16 cell lines, the 3 fresh specimens, and the direct bone marrow preparation had a common deletion of the short arm of chromosome #3. Use of the shortest region of overlap analysis showed the common deletion was of the short arm in the regions p(14-23). This specific chromosomal abnormality, del 3p, was not found in five non-SCLC cell lines studied and is of major potential biological and diagnostic importance.

Carcinoma, Small Cell↗
PubMed1982

A model for competency-based, computer-managed instruction in allied health.

A competency-based, computer-managed instruction model was developed and used in revising and managing the curricula of dietetic internship and physical therapy certificate programs. Use of the model resulted in identification and validation of program competencies and performance criteria, revision of curricula, and implementation of a computer-managed instructional support system to record, store, and provide feedback to students and instructors about performance on the competency measures. Improvements in the quality of the curricula and in the ability to manage student performance information have resulted from these efforts. The computer-managed instruction system has been well received by instructors and students. The most obvious benefits include savings in time for instructors and immediate feedback on performance for students. Results indicate that a competency-based, computer-managed approach to curriculum development and implementation is desirable and practical and has the potential for effectively serving future developments in allied health education.

Allied Health Personnel↗
PubMed1982

Minimal surgery for chronic obstruction in patients with extensive or universal Crohn's disease.

Patients with extensive chronic Crohn's disease of the small bowel, who may have had repeated excisional surgery, sometimes develop intestinal obstruction due to the development of a stricture. Surgery is usually thought to be contraindicated since further resections would leave the patient with insufficient small intestine to maintain a normal state of nutrition. Nine such patients have been treated since 1979 by operations which have been designed simply to relieve the obstruction. After careful preparation with intravenous alimentation, clearing the intestine of its contents, and the use of prophylactic antibodies the strictures were treated with minimal excisions, enteroenterostomies, and 'strictureplasties' according to their length and the degree of inflammation. In spite of the apparent danger of carrying out the operations through active Crohn's inflammation there have been no fatalities or major complications and the long-term results have been good.

Adult↗