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Biomedical subjects

M Taubman

Publications and source records attributed to M Taubman.

7 recordsLinked to original sources
PubMed2002

Tissue factor deficiency causes cardiac fibrosis and left ventricular dysfunction.

Exposure of blood to tissue factor (TF) activates the extrinsic (TF:FVIIa) and intrinsic (FVIIIa:FIXa) pathways of coagulation. In this study, we found that mice expressing low levels of human TF ( approximately 1% of wild-type levels) in an mTF(-/-) background had significantly shorter lifespans than wild-type mice, in part, because of spontaneous fatal hemorrhages. All low-TF mice exhibited a selective heart defect that consisted of hemosiderin deposition and fibrosis. Direct intracardiac measurement demonstrated a 30% reduction (P < 0.001) in left ventricular function in 8-month-old low-TF mice compared with age-matched wild-type mice. Mice expressing low levels of murine FVII ( approximately 1% of wild-type levels) exhibited a similar pattern of hemosiderin deposition and fibrosis in their hearts. In contrast, FIX(-/-) mice, a model of hemophilia B, had normal hearts. Cardiac fibrosis in low-TF and low-FVII mice appears to be caused by hemorrhage from cardiac vessels due to impaired hemostasis. We propose that TF expression by cardiac myocytes provides a secondary hemostatic barrier to protect the heart from hemorrhage.

Animals↗
PubMed1999

Cooperation between VEGF and TNF-alpha is necessary for exposure of active tissue factor on the surface of human endothelial cells.

This study was undertaken to characterize tissue factor (TF) induction, localization, and functional activity in cultured human umbilical vein endothelial cells (HUVECs) exposed to recombinant vascular endothelial growth factor (rVEGF) and recombinant tumor necrosis factor-alpha (rTNF-alpha). rVEGF (1 nmol/L) and rTNF-alpha (500 U/mL) synergistically increased TF mRNA, protein, and total activity, as measured in cell lysates. To examine surface TF expression, living cells were treated with antibody to TF and examined microscopically. Almost no staining was seen in control cells or cells treated with a single agent. In contrast, cells treated with both agonists showed intense membrane staining with surface patches, appearing as buds by confocal microscopy. To determine surface TF activity, studies were performed using a parallel-plate flow chamber, which allows detection of factor Xa generation on living cells. rVEGF and rTNF-alpha induced little surface TF activity (0.032+/-0.008 and 0.014+/-0.008 fmol/cm2, respectively). In combination, they significantly increased TF expression on the cell surface (0.429+/-0.094 fmol/cm2, P<0.05). These data indicate that the synergistic effect of rVEGF and rTNF-alpha is necessary to generate functional TF on the surface of endothelial cells. The requirement for multiple agonists to expose active TF may serve to protect endothelial cells from acting as a procoagulant surface, even under conditions of cell perturbation.

Antigens, Surface↗
PubMed1992

Transfer of staff training from workshops to group homes: a failure to generalize across settings.

Two experiments were conducted to assess acquisition and generalization of skills acquired in a workshop by trainees who were primary caregivers on the staffs of group homes for developmentally disabled clients. In Study 1, 31 staff trainees received an intensive, 1-week workshop in behavioral theory and treatment techniques. When assessed at the workshop site, these staff trainees showed increased treatment skills, relative to 18 staff trainees who did not participate in the workshop. In Study 2, pre- and postworkshop observations were taken on 53 developmentally disabled clients in group homes where the staff trainees worked. These observations provided no evidence that the workshop had any effect on group home client functioning. Future training programs for caregivers may be more successful if they occur in the group home, involve clients in the home, and enlist the support of supervisory staff, rather than focusing only on primary caregivers.

Activities of Daily Living↗
PubMedDate not supplied

The effectiveness of a group discrete trial instructional approach for preschoolers with developmental disabilities.

Group behavioral classroom instruction for children with developmental disabilities has been shown to allow for increased efficiency, approximation to naturalistic arrangements, and enhanced opportunity for interaction, social teaching and observational learning. This study examines the effectiveness of a group instructional extension of one to one discrete trial teaching, which involves the overlapping of trials between students along with the use of sequential and choral group teaching. A multiple baseline design across tasks was employed to examine the effectiveness of the group instructional approach in promoting acquisition of educational skills among preschoolers with autism and other developmental disabilities. A time sample interval assessment of components of the group instruction was also conducted. The approach was demonstrated to consistently increase correct responding across the task areas. Results are discussed in terms of the advantages of the group instructional approach as an adjunct to one to one discrete trial instruction.

Child, Preschool↗