PubMed Health⌕ Search

Biomedical subjects

P D Green

Publications and source records attributed to P D Green.

17 recordsLinked to original sources
PubMed2001

Antagonistic regulation of Dlx2 expression by PITX2 and Msx2: implications for tooth development.

The transcriptional mechanisms underlying tooth development are only beginning to be understood. Pitx2, a bicoid-like homeodomain transcription factor, is the first transcriptional marker observed during tooth development. Because Pitx2, Msx2, and Dlx2 are expressed in the dental epithelium, we examined the transcriptional activity of PITX2 in concert with Msx2 and the Dlx2 promoter. PITX2 activated while Msx2 unexpectedly repressed transcription of a TK-Bicoid luciferase reporter in a tooth epithelial cell line (LS-8) and CHO cell line. Surprisingly, Msx2 binds to the bicoid element (5'-TAATCC-3') with a high specificity and competes with PITX2 for binding to this element. PITX2 binds to bicoid and bicoid-like elements in the Dlx2 promoter and activates this promoter 45-fold in CHO cells. However, it is only modestly activated in the LS-8 tooth epithelial cell line that endogenously expresses Msx2 and Pitx2. RT-PCR and Western blot assays reveal that two Pitx2 isoforms are expressed in the LS-8 cells. We further demonstrate that PITX2 dimerization can occur through the C-terminus of PITX2. Msx2 represses the Dlx2 promoter in CHO cells and coexpression of both PITX2 and Msx2 resulted in transcriptional antagonism of the Dlx2 promoter. Electrophoretic mobility shift assays demonstrate that factors in the LS-8 cell line specifically interact with PITX2. Thus, Dlx2 gene transcription is regulated by antagonistic effects between PITX2, Msx2, and factors expressed in the tooth epithelia.

Animals↗
PubMed2000

First step: report on a pilot course for personal and professional development.

OBJECTIVE: To describe a pilot course in personal and professional development, entitled 'Becoming a doctor: the first step' and our suggestions for what might be incorporated into future courses. SETTING AND CONTEXT: Leeds Medical School begins a new curriculum in September 1999 with a proportion of the first 3 years being devoted to a new module on personal and professional development. This module will include courses involving communication skills, ethics, working in groups and early patient contact through community visits. Some of these topics were piloted in a short course for first-year medical students in 1998. LEARNING METHODS: The course ran for 9 weeks and was largely experiential. The group facilitators came from diverse health and social care backgrounds. A variety of learning methods were used, concentrating on self-reflection, discussion, community visits and information gathering. EVIDENCE FOR EFFECTIVENESS: The views of both facilitators and students were analysed. Students particularly appreciated the community visits and group work. The facilitators were positive about the course overall while suggesting improvements, including their own involvement in future development of the course. CONCLUSIONS: The pilot course has helped us to focus on objectives for the new curriculum and to plan the new course. In particular there is a need for more attention to be given to the involvement of facilitators in course development.

Community Medicine↗
PubMed1990

Binding of isolated plant lectin by rhizobia during episodes of reduced gravity obtained by parabolic flight.

Development of a legume root nodule is a complex process culminating in a plant/bacterial symbiosis possessing the capacity for biological dinitrogen fixation. Formation of root nodules is initiated by the binding and stabilization of rhizobia to plant root hairs, mediated in part by a receptor/ligand recognition system composed of lectins on the plant root surface and lectin-binding sites on the rhizobial cell surface. The dinitrogen fixation activity of these root nodules may be an important feature of enclosed, space-based life support systems, and may provide an ecological method to recycle nitrogen for amino acid production. However, the effects on nodule development of varied gravitational fields, or of root nutrient delivery hardware, remain unknown. We have investigated the effects of microgravity on root nodule formation, with preliminary experiments focused upon the receptor/ligand component. Microgravity, obtained during parabolic flight aboard NASA 930, has no apparent effect on the binding of purified lectin to rhizobia, a result that will facilitate forthcoming experiments using intact root tissues.

Fabaceae↗
PubMed1981

Black services in community mental health centers: a need for technical assistance.

The experiences of two black mental health professionals, who were invited to provide technical assistance to improve services to blacks in three community mental health centers in South Carolina, are described. This was a new and unprecedented attempt to elucidate and correct the problems of inadequate mental health services for blacks, while improving compliance with affirmative action. Camouflaged in elite professionalism were subtle hostile feelings and negative beliefs about blacks.

Black or African American↗
PubMed1974

Neuronal ceroid-lipofuscin storage in Siamese cats.

The clinico-pathological findings of a nervous disease in two mature Siamese cats are described. In one animal intermittent convulsions and mania over a period of three weeks terminated in death, while in the other irritability and hind leg weakness were the main clinical features. Neuronal cytoplasmic inclusions composed of a complex lipid material were detected microscopically. The ultrastructure and staining reactions of these inclusions in one cat were similar to the curvilinear bodies described in neurovisceral storage disease in humans and in a neuronal lipodystrophy of cattle. The deposit was considered likely to be related to ceroid-lipofuscin. No differences in brain lipid quantity or quality could be detected when compared to two control cats.

Animals↗