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Biomedical subjects

D Peters

Publications and source records attributed to D Peters.

178 records · Page 10Linked to original sources

Promoting critical thinking skills.

Educational accountability requires examination and justification of curriculum elements that will promote critical thinking skills. The authors review theoretical components of critical thinking and provides four examples of teaching strategies used to enhance this cognitive skill.

Decision Making↗

Active learning strategies to teach case management.

Changes in healthcare delivery require a new understanding of the concepts of case management in managed care. The authors describe the construction and evaluation of a learning module that encourages active engagement and skill development. Students develop an understanding of how to plan for care of populations in an effort to meet managed care demands. This approach to teaching case management can be effective in an educational setting and possibly in clinical settings as well.

Case Management↗

Vitrification of human spermatozoa without cryoprotectants.

The aim of our study was to investigate the effects of vitrification (cooling rate approximately 10000(C/min) without cryoprotectants on swim-up prepared human spermatozoa in comparison to standard conventional freezing with cryoprotectants. Motility, morphology, rate of viability and acrosome reaction of spermatozoa were evaluated. The described method of cryopreservation of human spermatozoa by direct plunging into liquid nitrogen slush without cryoprotectants was effective and could be recommended for routine IVF.

Cell Survival↗

Xenogeneic and allogeneic canine heart transplantation: a model for cytologic and immunologic monitoring of rejection mechanisms.

In the model of heterotopic intrathoracic heart transplantation, rejections of the graft are not lethal for the recipient animal. Therefore it is possible to follow the immunologic rejection mechanism to the final stage. Allogeneic dog hearts (n = 6) and xenogeneic fox hearts (n = 6) were transplanted. Immunosuppression therapy included cyclosporine and methylprednisolone. Cytoimmunologic monitoring was done every second day. Due to fluctuations of lymphocyte subpopulations and their immature forms, endomyocardial biopsies were performed. The transplanted allogeneic hearts survived for 53.2 +/- 14.8 days if treated with cyclosporine (historical control group without immunosuppression 6.8 +/- 0.8 days). Xenogeneic fox hearts stopped beating after 20.2 +/- 4.1 days (historical control 8.4 +/- 1.9 days). The allogeneic grafts were all rejected in an acute cellular fashion, whereas xenogeneic transplanted hearts showed humoral and cellular rejection mechanisms. Monitoring of circulating inflammatory cells allowed differentiation between humoral and cellular rejection, which was confirmed by histology. Both types of rejection were accompanied by an increase of lymphocytes and their activated forms. Differentiation of lymphocyte subpopulations revealed a significant increase of surface IgG-positive B-lymphocytes under humoral rejection, whereas acute cellular rejection episodes showed a substantial increase of surface IgG-negative lymphocytes. Humoral rejection that developed even with cyclosporine administration was not influenced, whereas cellular rejections were controlled by increasing methylprednisolone to 250 mg/day for 3 days.

Animals↗

Comparative cytophotometric analysis of reactive lymphoid hyperplasia and low malignant non-Hodgkin lymphoma.

In fine needle aspiration biopsy (FNAB) of lymph nodes, differential diagnosis between reactive lymphoid hyperplasia (RLH) and low grade non-Hodgkin lymphoma (NHL) may be sometimes difficult. Cytophotometric analysis of DNA content using image analysis has found practical application in the determination of malignancy in different tumours. In this study, image cytometry was applied to compare the ploidy status of the above mentioned lesions to obtain diagnostically helpful information. Thirty smears of histologically proven low grade NHL (10 follicular lymphomas of centroblastic-centrocytic type, 10 lympho-plasmocytoid immunocytomas, 10 chronic lymphocytic leukemias) and 15 smears of RLH were stained with Feulgen and examined by image analysis (CAS 200, Becton Dickinson). The 5c exceeding rate was determined according to the Boecking's definition of aneuploidy. Concerning the histogram types the Auer classification was used. The aneuploidy was found in 4/10 follicular lymphomas and 4/10 lymphoplasmocytoid immunocytomas. All chronic lymphocytic leukemias were diploid. In none RLH a 5c exceeding rate was found. The results verify the value of image cytophotometry as a helpful method in some diagnostically difficult cases.

Adolescent↗