PubMed Health⌕ Search

Biomedical subjects

H Pham

Publications and source records attributed to H Pham.

At least 37 records · Page 2Linked to original sources

Creating tobacco control policy at the local level: implementation of a direct action organizing approach.

This article describes the community activation and policy change process in seven Minnesota communities involved in the Tobacco Policy Options for Prevention (TPOP) study. The study's intervention employed a direct action organizing model, which relies on mobilizing large numbers of people to alter decision making and leverage the power of elites. As part of the organizing process, TPOP organizers and teams made 1,319 personal contacts with community members, generated 309 media stories, and initiated 445 public events related to tobacco use. These actions resulted in the establishment of comprehensive tobacco ordinances in all seven communities. The authors discuss the goals, training, activities and political factors relevant to four phases of the TPOP intervention: information gathering and team recruitment, community awareness building and ordinance development, preparing for city council, and ordinance establishment and enforcement. Included are suggestions for practitioners interested in using policy change and community-based advocacy to resolve public health problems.

Adolescent↗

Bladder injury model induced in rats by exposure to protamine sulfate followed by bacterial endotoxin.

PURPOSE: A bladder injury model was developed using protamine sulfate (PS) and endotoxin lipopolysaccharide (LPS) administered intravesically to female Sprague-Dawley rats. MATERIALS AND METHODS: Experimental and control animals were catheterized and intravesically exposed to PS-LPS, PS, LPS, or phosphate buffered saline. After 4, 24 or 72 hours, rats were sacrificed. Urines and bladder tissues were then obtained. Bladder mucosal permeability was evaluated by measuring 14C-urea uptake 24 hours after injury. Repeated instillations of PS/LPS were also made in another group of rats over a period of 5 weeks to attempt to establish a more serious mucosal injury, possibly reflected by altered staining of the collagen IV component of the urinary basement membrane (UBM). RESULTS: Histological examination of the tissues indicated a maximal inflammatory response in the mucosa 4 hours after instillation of PS/LPS. Neutrophils and macrophages in close proximity to the UBM and intraepithelially could be demonstrated. Bladder permeability was significantly altered (26.9% 14C-urea uptake) in rats assayed 24 hours after the PS/LPS treatment, but not after exposure to PS or LPS alone (11.9 and 17.5%, respectively). Protease activity detected in urines from experimental, but not control, animals coincided with the appearance of inflammatory cells in the lamina propria. Inflammatory injury did not appear to alter the collagen IV staining of the UBM. CONCLUSIONS: This rat bladder injury model is useful for examining controversial issues regarding bladder wall structure-function alterations induced by inflammation and possibly important in the pathobiological mechanisms involved in some patients with interstitial cystitis.

Animals↗

Cost-effectiveness of hospice care.

Is hospice cost-effective? What is perfectly clear is that hospice care overall provides different care than conventional care for the dying. There is much more home care, aimed at goals of comfort, dignity, and remaining at home, and that care is distributed over longer periods of time. There is less hospital care and less anticancer therapy. Nonhospice oncologic care provides more hospital services, particularly in the last month of life, and more effort to directly attack the malignant disease. There will always be those individuals whose goals and medical condition at a particular time make one type of care the best choice for that person. Current research strongly supports hospice care as cost-saving in the last month of life. The overall effect of hospice care on costs appears to be weakly positive. This is despite the fact that hospice benefits under Medicare include absence of co-payment, medications for the primary condition, and substantially more supportive services, which represent extra value and decreased out-of-pocket expenses to the consumer. A factor strongly favoring the development of cost-effective programs is the fact that most hospices began and developed as capitated systems of care. Thus the benefits derived from providers working with patients to control costs have accrued over time. The not-for-profit structures led savings to be put back into patient care, allowing more help for families and patients. An unresolved bias of available research is the question of the extent to which hospice patients are self-selected at the time of entry for their low interest in intensive and expensive services. The most positive estimates of cost-savings in hospice have required case-mix or time-of-entry adjustments to demonstrate savings. There is little support for cost-savings in the raw data comparing total costs in hospice and conventional care groups. However, there is also no evidence that hospice care adds to costs of care for the dying. Differences in outcomes between hospice- and conventional-care have been modest. Satisfaction with care has often been higher in hospice care, but care giver burden may also be higher. Other outcome measures have been inconsistently affected. The task of measuring differences is a difficult one. Hospice patients themselves are largely unavailable for measurement during the most critical periods of care, and proxy measures of benefit are necessary. Families also tend to be grateful (or critical) around the death of a loved one; this is related to complex family relationships and emotions not likely to be influenced by any health care program. It should also be noted that the task of measuring the success of hospice care has largely used measures originally developed for understanding the impact of conventional oncologic care. The tools for understanding the effects of spiritual counseling or homemaker assistance are much less well developed. The initial goals of the Medicare hospice benefit appear to have been met: a choice is available that responds to the needs and concerns of many dying people and their families, at no additional cost to the taxpayer. In addition, millions of families have received the benefit of the lower out-of-pocket costs for health services and medications. They have benefited from the broader definition of health which made simple, continuous support services such as homemaking and personal care available at no charge. The question of hospice cost-effectiveness would seem to be a question of the past. Other questions offer even more substantial challenges to continuing hospice care as it is now offered and into the future. There are no data to allow a critique of the current structure of hospice services, or to support the link between individual components of service and outcomes. This leaves the hospice concept open to considerable manipulation.(ABSTRACT TRUNCATED)

Cost-Benefit Analysis↗

Demonstration of receptors for insulin-like growth factor binding protein-3 on Hs578T human breast cancer cells.

Hs578T human breast cancer cells are from an estrogen receptor-negative breast cell line derived from a highly aggressive mammary tumor. Our previous insulin-like growth factor binding protein-3 (IGFBP-3) binding studies (Oh, Y., Müller, H. L., Lamson, G., and Rosenfeld, R. G. (1993) J. Biol. Chem. 268, 14964-14971) have demonstrated specific binding of IGFBP-3 on the Hs578T cell surface and a significant inhibitory effect of IGFBP-3, itself, on monolayer growth. In this study, we have demonstrated cell surface association proteins that are specific for IGFBP-3 by showing: 1) detection of 20-, 26-, and 50-kDa proteins by affinity cross-linking with 125I-IGFBP-3E. coli and immunoprecipitation of cell monolayers and cell lysates with anti-IGFBP-3 antibodies; 2) dose-dependent competition of 125I-IGFBP-3E. coli by unlabeled IGFBP-3E. coli; 3) inhibition of IGFBP-3 binding to these cell surface proteins by EDTA and by coincubation with native insulin-like growth factor II (IGF-II), but not by coincubation with [Gln6,Ala7,Tyr18,Leu19,Leu27]IGF-II, an IGF-II analog with decreased affinity for IGFBP-3; and 4) partial purification of 20- and 26-kDa species by IGFBP-3.anti-IGFBP-3 antibody immunoaffinity membranes. Characteristics of these specific IGFBP-3 cell surface association proteins are identical to those observed in our previous monolayer binding assay and monolayer growth assay experiments. The specificity of binding and the inhibitory effect of IGFBP-3 binding on Hs578T cell growth suggest that these cell surface proteins are IGFBP-3-specific receptors or receptor subunits mediating the direct inhibitory effect of IGFBP-3 on monolayer growth of Hs578T cells.

Amino Acid Sequence↗

Insulin-like growth factors (IGFs) block FSH-induced proteolysis of IGF-binding protein-5 (BP-5) in cultured rat granulosa cells.

Rat granulosa cells (GC), in vitro, express IGFBPs under the influence of both FSH and IGF-I. The major IGFBP produced by GC is a 28-29 K IGFBP, presumed to be IGFBP-5. When GC-conditioned medium (GC-CM) was assessed by Western Ligand Blotting (WLB), FSH appeared to decrease IGFBP-5, whereas IGF-I appeared to increase IGFBP-5 and to partially block the effects of FSH treatment. When GC-CM from FSH-treated cells was incubated with pure IGFBP-4 and IGFBP-5, the amount of IGFBP-5 (measurable by WLB) was decreased. Similarly, when GC-CM from FSH-treated cells was incubated with iodinated IGFBP-4 and IGFBP-5, IGFBP-5 (but not IGFBP-4) was proteolyzed into fragments of approximately 18 and 14 K. The ability of FSH-treated GC-CM to proteolyze IGFBP-5 was reduced by the addition of IGF-I to the reaction mixture. When the IGFBPs in GC-CM were evaluated by affinity crosslinking, GC-CM from control cultures contained one band with an apparent M(r) of approximately 34 K, whereas GC-CM from FSH-treated cultures displayed a decrease in the intensity of the 34 K band, as well as a new band of approximately 24 K. These data suggest that rat GC cells produce an FSH-inducible IGFBP-5 protease activity, and reveal that the ability of this protease to cleave IGFBP-5 is blocked by IGFs.

Animals↗

Insulin-like growth factor binding protein (IGFBP)-3 levels in conditioned media of Hs578T human breast cancer cells are post-transcriptionally regulated.

Hs578T human breast cancer cells secrete insulin-like growth factor binding protein (IGFBP)-3 (41-kDa and 39-kDa) and IGFBP-4 (24-kDa) as major BP species. In addition, cell surface-associated IGFBP-3 is demonstrable by use of cell monolayer affinity cross-linking or by employing immunoperoxidase staining of the cell surface with specific polyclonal anti-human IGFBP-3 antibodies (alpha IGFBP-3gl and alpha IGFBP-3ngl). In this study, we have demonstrated that regulation of Hs578T IGFBP-3 by IGF peptides is specific, non-receptor mediated, and post-translational by showing: 1) dose-dependent increase of IGFBP-3 in conditioned media(CM) following addition of IGF-I and IGF-II (maximum 8-13-fold increase at 100 ng/ml concentration), but not by insulin up to 1 microgram/ml; 2) confirmation of IGF-induced increases in CM concentrations of IGFBP-3 by means of Western ligand blot, affinity cross-linking, and IGFBP-3-specific radioimmunoassay; 3) increase of IGFBP-3 in CM by addition of IGF analogs which retain full affinity for IGFBPs ([Leu27]IGF-II and [Tyr55,Gln56]IGF-I), but not by IGF analogs which have significantly decreased affinity for IGFBPs ([Gln3,Ala4,Tyr15,Leu16]IGF-I, [Gln6,Ala7,Tyr18,Leu19,Leu27]IGF-II and IGF-I/insulin hybrid); 4) no change in IGFBP-3 mRNA following addition of IGFs; 5) existence of metal ion-dependent IGFBP-3 specific protease in CM and protection of IGFBP-3 from protease by formation of [IGF:IGFBP-3] complexes; and 6) release of cell surface-associated IGFBP-3 into CM by addition of IGF peptides. These studies demonstrate that IGF peptides regulate CM concentrations of IGFBP-3 through non-receptor mediated events, including dissociation of cell surface-associated IGFBP-3 and protection of IGFBP-3 from protease activity.

Blotting, Northern↗

Insulin-like growth factors (IGFs): implications for aging.

The insulin-like growth factors (IGF)-I and IGF-II are peptides with structural homology to insulin and potent mitogenic and anabolic actions in vitro and in vivo. IGF-I levels are growth hormone (GH)-dependent and vary strikingly with age. IGF-I levels are typically low in infancy and childhood, increase dramatically during puberty, and then gradually decline with advancing age. Whether age-associated changes in GH production or sex steroid secretion, or other unknown factors, cause diminished IGF production in the elderly remains to be determined. In the brain, IGF-II appears to be the most prevalent IGF, but a truncated form of IGF-I also has been recognized. IGF actions are mediated by binding to a family of receptors, which includes the insulin receptor, the structurally homologous type I IGF receptor, and the IGF-II/M-6P receptor, all of which are found in the central nervous system. Additionally, the IGFs bind with high affinity to a family of IGF-binding proteins (IGFBPs). Of the six known IGFBPs, IGFBP-2 appears to be the major one in the mammalian brain and is a major component of CSF. Immunoreactive IGFBP-2 has been identified in astrocytes, and its mRNA has been identified in fetal and adult brain and choroid plexus. The IGFBPs transport the IGFs in serum and other body fluids and appear to regulate IGF access to receptors. In vivo regulation of IGFBPs includes tissue-specific proteases, which cleave specific IGFBPs, altering their affinities for IGF peptides.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

Not all insulin-like growth factor-binding proteins (IGFBPs) are detectable by western ligand blotting: case studies of PC12 pheochromocytoma and rat anterior pituitary IGFBPs and proteolyzed IGFBP-3.

We studied the limitations of the Western ligand blot (WLB) for detecting insulin-like growth factor-binding proteins (IGFBPs). PC12 rat pheochromocytoma cells and rat anterior pituitary cells (AP) secrete IGFBPs that cannot be detected by WLB. We used affinity labeling, WLB, dot blotting, competitive binding, ion exchange chromatography, and deglycosylation to characterize these IGFBPs. These IGFBPs were compared with pregnancy protease-derived IGFBP-3 fragments that also bind insulin-like growth factors (IGFs), but are not detectable by WLB. We showed that PC12 IGFBP is cationic, not glycosylated, with 25,500 mol wt reduced (18,500 unreduced), with high affinity for IGF-II and low affinity for IGF-I. It cannot be detected by WLB and is not a proteolytic derivative of other IGFBPs or IGF-II receptors. Its binding activity is not destroyed by sodium dodecyl sulfate (SDS) and heating. It binds to nitrocellulose and IGF-II after dot blotting, but not to IGF-II during WLB. AP also secrete an IGFBP(s) that was not detectable by WLB. AP IGFBPs, unlike those of PC12, have a higher mol wt, and at least one component is glycosylated. The failure of WLB to detect these proteins remains unexplained. Pregnancy protease-derived IGFBP-3 fragments also bind IGFs and are not detectable by WLB. However, they do electrotransfer to nitrocellulose. The failure of WLB to detect these fragments is probably due to proteolysis rendering the binding site susceptible to irreversible denaturation (under conditions of WLB) during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These data suggest that WLB, while valuable, may have significant limitations in specific cases. Other techniques must complement WLB for detection of IGFBPs in conditioned media and other biological specimens.

Affinity Labels↗

Non-receptor mediated, post-transcriptional regulation of insulin-like growth factor binding protein (IGFBP)-3 in Hs578T human breast cancer cells.

Hs578T human breast cancer cells secrete insulin-like growth factor binding protein 3 (IGFBP-3) as the major BP species. In addition, cell surface-associated IGFBP-3 is demonstrable by the use of cell monolayer affinity cross-linking or immunoperoxidase staining of the cell surface with a specific polyclonal anti-human IGFBP-3 antibody (alpha IGFBP-3 gamma 1). In this study, we have demonstrated that regulation of Hs578T IGFBP-3 by IGF peptides is specific, non-receptor mediated, and post-translational by showing: 1) dose-dependent increase of IGFBP-3 in conditioned media (CM) following addition of IGF-I and -II (maximum 13 fold increase at 100 ng/ml), but not by insulin up to 1 mg/ml; 2) no change in CM IGFBP-3 level by [Gln3,Ala4,Tyr15,Leu16] IGF-I, which has decreased affinity for IGFBPs; 3) no change in IGFBP-3 mRNA following addition of IGFs; 4) release of cell surface-associated IGFBP-3 into CM by the addition of IGFs, but not by [Gln3,Ala4,Tyr15,Leu16]IGF-I. These studies demonstrate that IGF peptides regulate CM concentrations of IGFBP-3 through non-receptor mediated dissociation of cell surface-associated IGFBP-3.

Blotting, Northern↗

Pressure ulcer, fibronectin, and related proteins in spinal cord injured patients.

Pressure ulcer is a common occurrence in spinal cord injured (SCI) patients and can lead to serious complications. With proper management, some patients exhibit satisfactory healing whereas others show slow or nonhealing ulcers. Fibronectin has been shown to accumulate in wound, opsonize macroaggregate debris for phagocytosis, promote revascularization, and facilitate fibroblast migration and proliferation. We explored the relationship of plasma fibronectin with healing potential in 21 SCI men with pressure ulcer. They received standard wound care and were observed for eight weeks. Ten otherwise healthy SCI men without pressure ulcer (SCI-controls) and 32 able-bodied normal individuals (normal controls) were also studied. Plasma fibronectin and related proteins, ie, fibrinogen, plasminogen, alpha 2-antiplasmin and Factor XIII, were measured. Ten of 21 SCI patients with pressure ulcer showed rapid healing within four weeks and had significantly higher fibronectin levels as compared with the 11 patients with poor healing ulcers, SCI controls, and normal controls. Factor XIII and alpha 2-antiplasmin were mildly reduced and fibrinogen values were significantly increased in all SCI groups. Plasminogen concentrations were comparable in all groups studied. It thus appears that plasma fibronectin rises in patients with fast healing ulcers but fails to do so in those with poor healing ulcers and as such may be predictive of the course of pressure ulcers.

Adult↗

Aggressive fibromatosis of the maxilla. Report of a case and review of the literature.

Aggressive fibromatosis is a rare tumor of the jaws. Its occurrence in the maxilla is even more exceptional. The case of a 14-year-old girl with a peripheral fibromatosis of the palatal process of the maxilla is described. The lesion manifested as a painless swelling. On initial excision, a diagnosis of fibroma was made. After recurrence and reevaluation of the microscopic slides, a final diagnosis of aggressive fibromatosis was established. The features of this case and 12 similar lesions of the maxilla previously described in the literature are analyzed and discussed.

Adolescent↗

Identification of insulin-like growth factor-binding protein-2 (IGF-BP-2) and a low molecular weight IGF-BP in human seminal plasma.

Three distinct binding proteins for the insulin-like growth factors (IGF-BPs) have recently had their cDNAs cloned and sequenced. We have evaluated IGF-BP expression in normal, oligospermic and azospermic human seminal plasma (SP), and have identified IGF-BP-2 in all samples. Additionally, SP contains a non-glycosylated low molecular weight IGF-BP (24K), which does not appear to be structurally or immunologically related to IGF-BP-1, -2 or -3.

Base Sequence↗