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Biomedical subjects

R Vaughn

Publications and source records attributed to R Vaughn.

9 recordsLinked to original sources
PubMed1998

A new school-based program to provide eyeglasses: childsight.

OBJECTIVE: To address the unmet need for glasses encountered in an urban school setting by developing and implementing a school-based, cost-effective program that provides appropriate spectacle correction to needy children. METHODS: A total of 5851 students 9 to 15 years of age in 4 middle schools in northern Manhattan were screened for vision. Those with vision worse than 20/40 were examined, given glasses if appropriate, or referred for additional evaluation. RESULTS: Of the 5851 children screened, 1614 (28%) had a failing result, with visual acuity less than 20/40 in the worse eye. Of this group, 1082 were given glasses that were assembled at the school within 1 hour of testing. Ten percent of the group that required glasses already had them, and the remaining were referred for a complete ophthalmic examination that was completed in 58 cases. Only 14 of these had vision loss unrelated to refractive error. CONCLUSIONS: The program successfully treated 88.3% of the children within the school who needed glasses. Given that only 10% of children who needed glasses had them, it indicates a huge need to provide glasses to at least a million children in this age group in the United States.

Adolescent↗
PubMed1998

Dietary energy restriction in the SENCAR mouse: elevation of glucocorticoid hormone levels but no change in distribution of glucocorticoid receptor in epidermal cells.

The purpose of this study was to demonstrate that dietary energy restriction elevates plasma glucocorticoid hormone (GCH) levels while maintaining a circadian profile. Furthermore, we indirectly measured the effect of energy restriction on receptor activation in epidermis by determining the cellular localization of receptor protein in control-fed and energy-restricted (ER) mice. SENCAR mice were maintained on an ad libitum control diet or an ER diet that provided 60% of the total energy consumed by control-fed mice. Plasma corticosterone levels were determined by radioimmunoassay. Glucocorticoid receptor (GR) protein levels in epidermal lysates were measured by western blotting. Electron microscopy was used to identify gold-conjugated immunoreactive GR in epidermal cells of the skin in control and ER mice. Plasma corticosterone levels in ER mice were significantly increased 10 times over the levels in control mice at 0700 h, significantly increased two times over control levels at 1600 h, and not different from controls at 2300 h in the circadian cycle. The total amount of epidermal GR protein in ER mice was 140% (95% confidence interval, 104-169%) of that in controls at the early time point, not different at the midpoint, and 60% (95% confidence interval, 48-79%) of that in controls at the late time point. The distribution of gold-conjugated GR in the cytoplasmic and nuclear compartments of epidermal cells was similar in control and ER mice. Thus, we showed that dietary ER increased the level of plasma GCH without abolishing diurnal variation. However, an increase in ligand activation in epidermal cells, as indicated by nuclear localization of GR protein, was not supported by the results of this study.

Aldosterone↗
PubMed1998

Methodology of quality improvement projects for the Texas Medicare population.

The Texas Medical Foundation, the quality improvement organization for the state of Texas, develops local quality improvement projects for the Medicare population. These projects are developed as part of the Health Care Quality Improvement Program undertaken by the Health Care Financing Administration. The goal of a local quality improvement project is to collaborate with providers to identify and reduce the incidence of unintentional variations in the delivery of care that negatively impact outcomes. Two factors are critical to the success of a quality improvement project. First, as opposed to peer review that is based on implicit criteria, quality improvement must be based on explicit criteria. These criteria represent key steps in the delivery of care that have been shown to improve outcomes for a specific disease. Second, quality improvement must be performed in partnership with the health care community. As such, the health care community must play an integral role in the design and evaluation of a quality improvement project and in the design and implementation of the resulting quality improvement plan. Specifically, this article provides a historical perspective for the transition from peer review to quality improvement. It discusses key steps used in developing and implementing local quality improvement projects including topic selection, quality indicator development, collaborator recruitment, and measurement of performance/improvement. Two Texas Medical Foundation projects are described to highlight the current methodology and to illustrate the impact of quality improvement projects.

Angina Pectoris↗
PubMed1995

Identification of protein kinase C zeta isozyme in hamster pancreas and pancreatic carcinoma cell lines.

Cellular differentiation and proliferation are dependent upon phosphorylation by endogenous protein kinase C (PKC) isozymes in many cell types. Western blotting with a C-terminally directed rabbit polyclonal anti-PKC zeta antibody detected a doublet of approximately 81 kDa in normal hamster pancreatic tissue and hamster pancreatic carcinoma (PC-1) and human pancreatic carcinoma (PANC-1) cells. Preabsorption of the antibody with the specific peptide blocked the appearance of the 81-kDa band, indicating that the band was specifically recognized by the PKC zeta antibody. In contrast, antibodies for PKC alpha, beta, gamma, delta, and epsilon failed to show specific immunoreactivity for normal pancreatic tissue or PANC-1 or PC-1 cells. Immunocytochemical analysis identified PKC zeta in the cytoplasm of ductules and large ducts, to a lesser extent in the islets of the hamster pancreas, and in the normal cultured pancreatic duct epithelial cells and pancreatic carcinoma (PANC-1 and PC-1) cell lines. Specific reactivity was seen by electron microscopy in the ductal cells of the normal pancreatic tissue. In normal pancreatic ductal tissue and primary pancreatic ductal hyperplasia and carcinoma, the proportional labeling of PKC zeta in nuclei and cytoplasm was similar. Our results demonstrating the presence of PKC zeta isozyme in the normal pancreas, cultured normal pancreatic duct epithelial cells, and pancreatic carcinoma cells or carcinoma tissue suggests a role for this isozyme in the normal physiology of the pancreas and perhaps in pancreatic carcinoma.

Amino Acid Sequence↗
PubMed1995

Cellular and subcellular localization of transforming growth factor-alpha and epidermal growth factor receptor in normal and diseased human and hamster pancreas.

Four normal pancreas, 8 chronic pancreatitis specimens, and 30 non-endocrine pancreatic tumors from humans and 6 normal and 6 induced pancreatic cancers in hamsters were examined immunohistochemically by antibodies against human transforming growth factor-alpha (TGF-alpha) and epidermal growth factor receptor (EGFR). Two normal pancreas and two pancreatic cancer specimens from each species were also studied immunoelectron microscopically by the immunogold method. In chronic pancreatitis, the reactivity and intensity of the staining with both antibodies were much greater in ductal/ductular cells than in the normal pancreas. All 30 pancreatic cancers reacted with both antibodies with a variable degree of reactivity and staining intensity. No correlation was found between the histological type of tumors, the degree of tumor differentiation, and the incidence and patterns of reactivity of either antibody. Immunoelectron microscopically, both EGFR and TGF-alpha were demonstrated primarily on the basal membrane. In the normal hamster pancreas, TGF-alpha was overexpressed in the alpha-cells but not in any other islet cells. Both TGF-alpha and EGFR were marginally detectable in the exocrine pancreas and in induced pancreatic lesions. This is the first demonstration of subcellular localization of TGF-alpha and EGFR in the normal and diseased human and hamster pancreas.

Adult↗
PubMed1994

Expression of the murine plasma cell nucleotide pyrophosphohydrolase PC-1 is shared by human liver, bone, and cartilage cells. Regulation of PC-1 expression in osteosarcoma cells by transforming growth factor-beta.

A bone and cartilage enzyme with both 5'-nucleotide phosphodiesterase I and nucleotide pyrophosphohydrolase (NTPPPH) activity modulates physiologic mineralization and pathologic chondrocalcinosis by generating inorganic pyrophosphate. We hypothesized that, as for alkaline phosphatase, expression of an NTPPPH gene can be shared by cells from bone, cartilage, and liver and by certain leukocytes. Recently, we demonstrated the hepatocyte and murine plasma cell membrane glycoprotein PC-1 to have both 5'-nucleotide phosphodiesterase I and NTPPPH activity. We detected polypeptides cross-reactive with PC-1 in human U20S osteosarcoma cells, articular chondrocytes, homogenized human knee cartilages, human knee synovial fluids, hepatoma cells, and murine plasmacytoma cells. Constitutive low abundance PC-1 mRNA expression was detected in U20S cells and chondrocytes by a nested RNA-PCR assay and by Northern blotting. TGF beta is known to substantially increase NTPPPH activity in primary osteoblast cultures. We demonstrated that TGF beta 1 increased NTPPPH activity and the level of PC-1 mRNA and immunoprecipitable [35S]-methionine-labeled PC-1 polypeptides in U20S cells. The identification of PC-1 as an NTPPPH expressed in cells derived from bone and cartilage may prove useful in furthering the understanding of the role of NTPPPH i n physiologic and pathologic mineralization.

Animals↗