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Ohne Zusammenfassung     

Coping with dental treatment: The potential impact of situational demands

Coping strategies and anxiety responding of dental patients were studied in order to test the generalizability of previous findings based on volunteer blood donors. State and trait coping measures were administered once, and a process coping scale was administered at three points throughout treatment. Self-report, behavioral observation, and psychophysiological measures of anxiety were sampled for the same periods as process coping. Findings included the replication of a negative relationship between avoidant coping and patient anxiety ratings. Fluctuations in coping were evident across periods, and impact of situational demands and constraints was introduced as an explanation for these variations. A method for direct assessment of coping consistency was introduced. On the basis of the replicable associations with anxiety measures, the ability to detect changes in coping within a situation, and the ability to provide direct evidence of coping consistency, the use of process methodology for coping assessment is encouraged.This research was conducted while the first author was supported by funding from the Medical Research Council of Canada.Portions of this research were presented at the annual convention of the Society of Behavioral Medicine, Philadelphia, 1984.     

SV40-related T-antigen expression in human meningiomas with normal and G-22-monosomic karyotype.

Six of 16 meningiomas tested in early subcultures by indirect immunofluorescence showed SV40 T-antigen. Two different antisera specific for T-antigen were used. One serum gave a positive reaction with six tumours and the other with only two. In one T-antigen positive meningioma, the typical nuclear fluorescence changed, beginning with the second subculture, into an unusual brilliant granular pattern irregularly distributed over the nuclei. In six meningiomas, a specific chromosome aberration (monosomy G 22) was established. However, up to now, no clear correlation between karyotype and T-antigen expression could be found: cells from three meningiomas with positive reactions had normal karyotypes, whereas those from three tumours with typical chromosome loss showed no T-antigen.     

Imbalance of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinases: a novel approach for explaining the parenchymal liquefaction of the septic spleen?

OBJECTIVE: The causal pathophysiological mechanisms involved in the parenchymal liquefaction of the septic spleen are still far from clear. The balance between matrix metalloproteinases (MMPs) and their inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), is largely responsible for the remodelling of tissues. Deregulation of this balance is a characteristic of extensive tissue degradation in certain chronic inflammatory diseases. METHODS: This study focuses on a search for alterations in the balance between MMP-1 (interstitial collagenase) and TIMP-1 by means of immunostaining, by immunoblotting, and by gel zymography. RESULTS: We found a deregulation of the balance between MMP-1 and TIMP-1 in the septic spleen in favor of the active form of MMP-1. CONCLUSION: Our findings suggest that active MMP-1 is involved in collagenolytic extracellular matrix breakdown in the septic spleen.     

Selectivity of excitotoxic mechanisms in Alzheimer's disease

Dysfunction of glutamatergic neurons in Alzheimer's disease may actually participate in some of the neurodegenerative processes via potential excitotoxic mechanisms. Two hypotheses are advanced which describe how a generalized excitotoxic mechanism could interact with unique metabolic properties of specific cell types leading to their selective vulnerability in Alzheimer's disease.     

Characterization of SV40 enhancer motifs involved in positive and negative regulation of the constitutive late promoter activity; effect of T-antigen.

By analyzing the late promoter activity of a series of nonreplicative recombinants mutated within the different enhancer motifs of SV40 we identified both positive and negative regulatory elements. In the absence of T-antigen, the motifs Sph and/or octamer, and to a lesser extent the motifs GTI and P, account for the constitutive expression of the late promoter. The motif GTII overlaps elements that negatively regulate the expression of the late promoter. These results indicate that the late promoter is down-regulated not only at the level of the GC motifs but also at the enhancer level. Moreover, we showed that T-antigen interacts with both positive and negative regulatory elements.     

The polymorphism of HLA-DR3 in South African populations

The polymorphism of HLA-DR3 was investigated in families and unrelated individuals of three population groups: South African (SA) Negroes, Cape Coloureds and SA Caucasoids. Serological and restriction fragment length polymorphism (RFLP) analysis indicated that DR3 could be subdivided into DRw17 (previously DR3.1) and DRw18 (previously DR3.2). In contrast, the two-dimensional (2-D) gel electrophoresis patterns could not distinguish between the DRB1 gene products of the HLA-DRw17 and DRw18 cells. Two DRB3 variants, correlating with the T-cell defined specificities Dw24 and Dw25 were identified at the genomic and product level. Of ten haplotypes studied with the newly defined HLA-DRw18 specificity, all had the DRB3 RFLP pattern associated with Dw24. HLA-DRw17 was found in all three population groups tested, although in the SA Negroes HLA-DRw18 was the prevalent DR3 subgroup. This subgroup was also present in the Cape Coloureds but was absent in the SA Caucasoid tested. HLA-DRw18 forms part of the most characteristic SA Negro haplotype, Bw42, DQw4, Dw“RSH,” while HLA-DRw17 is part of the classic Caucasoid haplotype, B8, DQw2, Dw3.     

Student's perceptions of a virtual PBL experience.

OBJECTIVE: Our purpose is to present findings regarding student attitudes towards a virtual PBL program used to standardize their pediatric clinical experience. DESCRIPTION: With funding provided by the Fund for the Improvement of Post-Secondary Education, we developed Project LIVE (Learning through Interactive Video Education), a CD-ROM/Web hybrid program that uses digital video cases to conduct "virtual" problem-based learning groups with students doing a clinical rotation in a remote setting. Cases were progressively disclosed by videos of patient/physician encounters on a CD-ROM. Groups of five students and a faculty facilitator collaborated, teaching each other within the discussion section of the program. We conducted a multifaceted evaluation of Project LIVE to study the impact of case modality or distance on student learning and attitudes. We placed students in one of three groups (1) a face-to-face group with a paper case (FFT), (2) a face-to-face group with a video case (FFV), and (3) a virtual group (VG) with the digital video case. We then studied student attitudes about the three teaching formats. Over a six-month period three education specialists, who were not a part of the development team, conducted eight focus groups lasting one hour to assess student attitudes about Project LIVE. No one from the project team was present during these groups, and an independent evaluator analyzed the notes taken by each focus group leader. DISCUSSION: Trends across the groups included the following: (1) Authenticity (video)-Students reported that the authenticity of the case was a critical feature and that, "seeing (videos) made learning more memorable." Virtual and FFV groups reported more confidence in their ability to recognize abnormal findings in their patients. "You can't expect to teach clinical exam skills with a piece of paper." (2) Use of time-Students from all groups believed the cases were a good use of their time and improved their ability to solve clinical problems. They said it gave them an opportunity to "get away from just doing and focus on learning." However, the virtual groups complained of the lack of "a barometer for how much is too much" time. Some students reported spending an average of eight to ten hours per case over the period of a week. (In contrast, face-to-face groups met for three hours.) (3) Modeling clinical reasoning-Students believed the cases were valuable in structuring their knowledge, conceptualizing how to handle difficult situations, distinguishing abnormal from normal physical examination findings, and collaborating with their peers and their mentor to develop critical thinking. "It forced us to be logical" and ". how to think through the process-it mimics the real setting." (4) Technical support-The responsiveness of the Project LIVE staff was essential in assisting students in troubleshooting problems. (5) Distance component-Students preferred to work through the cases in face-to-face groups but agreed that the virtual experience is "good if you are in the middle of nowhere." This program was enjoyed by students and gave us an approach to standardizing experiences across multiple clinical sites.