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Biomedical subjects

C Anderson

Publications and source records attributed to C Anderson.

At least 91 records · Page 5Linked to original sources
PubMed1998

A randomized trial of an intervention to prevent lawnmower injuries in children.

The U.S. Consumer Product Safety Commission reports about 60,000 emergency room visits for lawnmower injuries annually with 20% to children under 15 years. Employing a randomized pre-post control group design, the current study evaluated a 20-minute video intervention to increase parents' (n = 80) safety awareness and preventive actions. The setting was an outpatient clinic at a Children's Hospital. Differences favoring the intervention group were found for four of six behavior outcomes. For example, the proportion reporting never allowing children near operating mowers increased from half to two-thirds with no change among comparison group parents. In addition, significant increases in severity beliefs were found. The results provide formative support for the video intervention which possesses the key advantages of ease of use and constancy of message.

Accidents, Home↗
PubMed1998

Mediating variable framework in physical activity interventions. How are we doing? How might we do better?

INTRODUCTION: Behavioral science provides the foundation for physical activity interventions. The mediating variable framework is used to assess the status of physical activity interventions and the roles that are, or could be played, by behavioral theory. METHODS: Twenty-five physical activity intervention studies and 45 physical activity correlational studies were found in the literature, tabulated, and included in the analysis. RESULTS: Behavioral interventions for promoting physical activity have worked primarily when participants were motivated enough to volunteer or when a school-based physical education program changed. In most cases, behavioral or psychosocial theory accounted for 30% or less of the variability in physical activity behaviors. Most intervention studies do not measure mediating variables, and when they do, they do not systematically effect changes in all the mediating variables on which they are predicated. DISCUSSION: To increase the effectiveness of physical activity interventions, more physical activity research should focus on a better understanding of the predictors of physical activity and toward interventions demonstrated to effect change in these predictors of physical activity. CONCLUSION: Changing the focus to basic behavioral and social science and mediator change research should provide a more systematic and cost-effective approach to increasing the effectiveness of physical activity interventions.

Adult↗
PubMed1998

Gastro-oesophageal reflux associated with nocturnal gastric acid breakthrough on proton pump inhibitors.

BACKGROUND: Nocturnal gastric acid breakthrough, defined as intragastric pH < 4 for more than 1 h in the overnight period, is observed in up to 70% of normal subjects on proton pump inhibitors taken twice daily. The frequency of this breakthrough in patients with gastro-oesophageal reflux and accompanying oesophageal reflux during this period has not been studied. AIM: To examine the frequency of nocturnal break-through and accompanying oesophageal acid exposure in patients with gastro-oesophageal reflux treated with proton pump inhibitors twice daily. METHODS: Prolonged ambulatory pH records from 76 patients on twice daily proton pump inhibitors between January 1991 and July 1997 were analysed for the presence of nocturnal gastric acid breakthrough and accompanying oesophageal pH < 4. Studies from 31 normal subjects on twice daily proton pump inhibitors constituted the control group. RESULTS: Nocturnal gastric acid breakthrough was seen in 70% of 61 patients with gastro-oesophageal reflux, 80% of 15 patients with Barrett's oesophagus and 67% of normal controls (P=N.S.). Oesophageal acid exposure was seen in 33% of gastro-oesophageal reflux patients, 50% of Barrett's oesophagus patients and 8% of normal controls (P < 0.03). No difference was found between patients taking omeprazole or lansoprazole. CONCLUSION: Nocturnal acid breakthrough is frequently seen on proton pump inhibitors twice daily and is often accompanied by oesophageal reflux. This has important implications for medical therapy in patients with severe gastro-oesophageal reflux and Barrett's oesophagus.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1998

Topical penetration of commercial salicylate esters and salts using human isolated skin and clinical microdialysis studies.

AIMS: The penetration of active ingredients from topically applied anti-inflammatory pharmaceutical products into tissues below the skin is the basis of their therapeutic efficacy. There is still controversy as to whether these agents are capable of direct penetration by diffusion through the tissues or whether redistribution in the systemic circulation is responsible for their tissue deposition below the application site. METHODS: The extent of direct penetration of salicylate from commercial ester and salt formulations into the dermal and subcutaneous tissue of human volunteers was determined using the technique of cutaneous microdialysis. We also examined differences in the extent of hydrolysis of the methylester of salicylate applied topically in human volunteers and in vitro skin diffusion cells using full-thickness skin and epidermal membranes. RESULTS: The present study showed that whilst significant levels of salicylate could be detected in the dermis and subcutaneous tissue of volunteers treated with the methylsalicylate formulation, negligible levels of salicylate were seen following application of the triethanolamine salicylate formulation. The tissue levels ofsalicylate from the methylsalicylate formulation were approx. 30-fold higher than the plasma concentrations. CONCLUSION: The absorption and tissue concentration profiles for the commercial methylsalicylate formulation are indicative of direct tissue penetration and not solely redistribution by the systemic blood supply.

Administration, Topical↗
PubMed1998

Estrogen receptor activation function 1 works by binding p160 coactivator proteins.

Estrogen receptor-alpha contains two transactivation functions, a weak constitutive activation function (AF-1) and a hormone-dependent activation function (AF-2). AF-2 works by recruiting a large coactivator complex, composed of one or more p160s, CREB-binding protein (CBP)/p300, and P/CAF (p300 and CBP-associated factor), via direct contacts with the p160s. We report here that independent AF-1 activity also requires p160 contacts. Unlike AF-2, which binds signature NR boxes in the center of the p160 molecule, AF-1 binds to sequences near the p160 C terminus. We propose that the ability of AF-1 and AF-2 to interact with separate surfaces of the same coactivator is important for the ability of these transactivation functions to synergize.

Acetyltransferases↗
PubMed1998

Patient assessment: a systematic approach.

Patient assessment is an important component of any nurse's role. It allows patient care to be prioritized in an appropriate manner and it forms the basis of nursing care plans both of which impact on patient outcomes.

Humans↗
PubMed1998

Proton MR spectroscopy in Lesch-Nyhan disease.

In vivo proton spectra for four patients with Lesch-Nyhan disease and four control subjects matched for age and sex were acquired from voxels (1.5 x 1.5 x 1.5 cm3) placed in the prefrontal cortex and striatum. The patients with Lesch-Nyhan disease had decreased metabolites, especially N-acetylaspartate and glutamate/glutamine, only in the prefrontal cortex as compared with the control group. These findings suggest axonal loss in the prefrontal area of this population. The cortical glutamate/glutamine peak decrement does not confirm cytopathologic studies of Lesch-Nyhan disease and deserves further investigation.

Adolescent↗
PubMed1997

Violence in television commercials during nonviolent programming. The 1996 Major League Baseball playoffs.

OBJECTIVE: To identify the frequency of violent television commercials aired during major league baseball playoffs, traditionally thought to be a family-oriented viewing time. DESIGN AND SETTING: All 6 World Series games televised on the Fox Television Network (Fox), all 5 American League Championship Series playoff games televised by the National Broadcasting Company (NBC), and 4 first-round playoff games televised by ESPN Sports Television Network (ESPN) were videotaped in October 1996. RESULTS: During the 15 televised games reviewed, 104 (6.8%) of the 1528 commercials contained violent content. Sixty-one commercials (10 per game) that included violent interactions were noted during the World Series, 30 (6 per game) during the American League Championship Series, and 13 (3 per game) during the 4 first-round playoff games for a total of 104. In these 104 violent commercials, 69 contained at least 1 violent act, 90 contained at least 1 violent threat, and 27 contained evidence of at least 1 violent consequence. Seventy (67.3%) of the violent commercials were promotions for television programs, 7 (6.7%) were cable television program advertisements, and 20 (19.2%) were big-screen movie promotions. Twenty (71.4%) of 28 big-screen movie promotions were violent. Twenty-two (21.2%) of the 104 violent commercials and 7 "nonviolent" commercials contained blood or other graphic content, all of which were televised during the Fox presentation of the World Series. Fox also accounted for all 24 violent commercials that used a knife. Guns were involved in 25 violent commercials on NBC (5.0 per game), in 20 on Fox (3.33 per game), and in 7 on ESPN (1.75 per game). CONCLUSION: Overt violent content in commercials during the 1996 major league playoffs was common and consisted mainly of promotions for television programs and big-screen movies. It is counterintuitive to find such commercials in nonviolent programming and makes it difficult for parents to avoid exposing their children to this form of violence.

Advertising↗
PubMed1997

Insulin signal transduction by a mutant human insulin receptor lacking the NPEY sequence. Evidence for an alternate mitogenic signaling pathway that is independent of Shc phosphorylation.

The cytoplasmic juxtamembrane domain of the human insulin receptor (hIR) contains a single copy of the tetrameric amino acid sequence Asn-Pro-Glu-Tyr (NPEY) (residues 969-972 in the exon 11-containing B-isoform), which exists in the context of NPXY. In this study, we examined the role of NPEY972 in mediating insulin signal transduction and cellular biological effects. Transfected Chinese hamster ovary cell lines expressing either the wild-type hIR-B isoform (hIR.WT) or a mutant receptor lacking the NPEY972 sequence (hIRDeltaNPEY) and control Chinese hamster ovary.Neo cells were used to comparatively analyze the following insulin effects: in vivo receptor tyrosine autophosphorylation and kinase activity, signal transduction to downstream signaling molecules, and stimulation of glycogen and DNA synthesis. The results showed that in comparison to hIR.WT, the hIRDeltaNPEY mutant demonstrated the following: (a) normal insulin-mediated receptor tyrosine phosphorylation, but approximately 50% reduction in phosphorylation of p185-(insulin receptor substrate-1) and binding of the p85 subunit of phosphatidylinositol 3-kinase (PI 3-kinase), (b) an enhanced stimulation of PI 3-kinase enzymatic activity, (c) a complete inability to phosphorylate Shc, (d) minimal impairment of insulin sensitivity for glycogen synthesis, and (e) an augmented response to insulin-stimulated DNA synthesis via a high capacity, low sensitivity pathway. These results demonstrate the following: 1) the NPEY972 sequence is important but not absolutely essential for coupling of hIR kinase to insulin receptor substrate-1 and p85 or for mediating insulin's metabolic and mitogenic effects, 2) the NPEY972 sequence is necessary for Shc phosphorylation, and 3) the absence of Shc phosphorylation releases the constraints on maximal insulin-stimulated mitogenic response, thus indicating that alternate signaling pathway(s) exist for this insulin action. This alternate pathway appears to be associated with enhanced activation of PI 3-kinase and is of high capacity and low sensitivity.

Animals↗
PubMed1997

Estrone sulfatase: probing structural requirements for substrate and inhibitor recognition.

The enzyme-catalyzed desulfation of steroids is a transformation that plays an important role in steroid biosynthesis. Conversion of steroid sulfates to unconjugated steroids may provide a source of steroids for processes such as steroid transport and the growth and proliferation of breast cancer. Steroid sulfatase catalyzes the hydrolysis of 3beta-hydroxysteroid sulfates. To identify structural features important in enzyme-inhibitor interaction, a variety of steroidal and non-steroidal phosphate esters were synthesized and tested as inhibitors of steroid sulfatase activity. We report that the basic structure for enzyme-inhibitor binding does not include the steroid nucleus. Furthermore, the hydrophobicity of the non-steroidal phosphates was determined to be an important factor for optimal inhibition. The monoanionic form of the phosphorylated compounds was found to be the inhibitory species. The best non-steroidal inhibitor of steroid sulfatase activity was n-lauroyl tryamine phosphate with a Ki of 3.6 microM and 520 nM at pH 7.5 and 7.0. The poorest non-steroidal based inhibitor of sulfatase activity was tetrahydronaphthyl phosphate with a Ki of 870 and 360 microM at pH 7.5 and 7.0.

Chromogenic Compounds↗
PubMed1997

Risk factors for post-stroke depression.

OBJECTIVE: To examine possible risk factors in post-stroke depression (PSD) other than site of lesion in the brain DATA SOURCES: 191 first-ever stroke patients were examined physically shortly after their stroke and examined psychiatrically and physically 4 months post-stroke. SETTING: A geographically defined segment of the metropolitan area of Perth, Western Australia, from which all strokes over a course of 18 months were examined (the Perth Community Stroke Study). MEASURES: Psychiatric Assessment Schedule, Mini Mental State Examination, Barthel Index, Frenchay Activities Index, physical illness and sociodemographic data were collected. Post-stroke depression (PSD) included both major depression and minor depression (dysthymia without the 2-year time stipulation) according to DSM-III (American Psychiatric Association) criteria. Patients depressed at the time of the stroke were excluded. PATIENTS: 191 first-ever stroke patients, 111 M, 80 F, 28% had PSD, 17% major and 11% minor depression. RESULTS: Significant associations with PSD at 4 months were major functional impairment, living in a nursing home, being divorced and having a high pre-stroke alcohol intake (M only). There was no significant association with age, sex, social class, cognitive impairment or pre-stroke physical illness. CONCLUSION: Results favoured the hypothesis that depression in an unselected group of stroke patients is no more common, and of no more specific aetiology, than it is among elderly patients with other physical illness.

Activities of Daily Living↗
PubMed1997

Hepatotoxicity of an HIV protease inhibitor in dogs and rats.

Oral administration of the HIV protease inhibitor L-689,502 caused cholestasis and hepatocyte injury in rats and dogs. These changes occurred rapidly, with elevations in serum transaminase observed as early as 6 hr after oral dosing in dogs. The acute phase of this hepatotoxic response was characterized in more detail in rats. Following intravenous administration, bile flow was decreased in a dose-dependent manner with greater than 90% decrease in less than 30 min at a dose of 5 mg/kg. The decrease in bile flow was associated with a decrease in erythritol clearance. The decrease in bile flow was not due to disruption of biliary tight junctions. Sucrose clearance was not increased and biliary bile acid concentrations in treated animals were not different from controls. Unlike control animals, bile flow was not stimulated by infusion of the bile acid tauroursodeoxycholic acid in animals treated with L-689,502. These cholestatic effects may be due, in part, to direct hepatocyte injury. Histological examination of perfusion-fixed livers 30 min after L-689,502 administration revealed periportal changes including hepatocyte vacuolation and occasional single cell necrosis. On a subcellular level, the nucleus and mitochondria were intact in less-severely affected cells. However, extensive vacuolation with multilamellar inclusions was pronounced in these cells. In addition, canalicular ectasia was also observed which was consistent with the cholestatic changes that were seen. In summary, L-689,502 is a potent, rapid acting hepatotoxin in dogs and rats. The mechanism by which this agent induces cholestasis is novel compared to other well-characterized cholestatic agents such as alpha-naphtylisothiocyanate and ethinyl estradiol.

Animals↗
PubMed1997

Tumour biological features of BRCA1-induced breast and ovarian cancer.

BRCA1 mutations, although implicated in disease predisposition in a major part of the hereditary breast cancer population, do not seem to be crucially involved in tumorigenesis of sporadic breast and ovarian cancers. This suggests that tumours arising in BRCA1 mutation carriers may differ from BRCA1 negative hereditary and sporadic cancer in genetic and biological features, as well as in clinical behaviour. Prior to BRCA1 analysis, 79 breast and 19 ovarian tumours from 57 breast and breast-ovarian cancer families, and 170 tumours from a comparison group of stage II breast cancers were studied with regard to histopathological features; immunohistochemistry [c-erbB-2, p53, oestrogen receptor (ER) and progesterone receptor (PR)], DNA flow cytometry and S-phase fraction. BRCA1 mutations were found in 40 breast and 15 ovarian tumours. The BRCA1 positive breast tumours were significantly more often of ductal type, histological grade III and manifested a heavy lymphocyte infiltration. Additionally, as compared to BRCA1 negative tumours, the BRCA1 positive tumours were significantly more often ER, PgR and c-erbB-2 negative. Furthermore, they were significantly more often DNA non-diploid, as well as being characterised by higher S-phase fraction values. These results suggest that BRCA1-induced breast cancers may manifest distinct tumour biological features of clinical importance.

Adult↗
PubMed1997

Phthalocyanine photodynamic therapy: disparate effects of pharmacologic inhibitors on cutaneous photosensitivity and on tumor regression.

The phthalocyanines are promising second-generation photosensitizers that are being evaluated for the photodynamic therapy (PDT) of malignant tumors. In vivo studies with the silicon phthalocyanine Pc 4 have shown that it is highly effective at causing regression of RIF-1 tumors in C3H/HeN mice in PDT protocols. Because cutaneous photosensitivity is the major complication of photosensitizers used for PDT, experiments were performed to evaluate the effect of inhibitors of the inflammatory response (cyproheptadine, dexamethasone, pentoxifylline, and tumor necrosis factor alpha [TNF-alpha] antibodies) on Pc 4-induced cutaneous photosensitivity and tumor regression. The C3H/HeN mice were injected with either Pc 4 or Photofrin and were exposed to 86 J/cm2 of filtered radiation emitted from a solar simulator. Animals were irradiated at 1, 3, 7, 10, 14 and 28 days postinjection. Cutaneous photosensitivity was assessed using the murine ear-swelling response. Cyproheptadine, dexamethasone, pentoxifylline and TNF-alpha antibodies were administered prior to illumination to assess their ability to block Pc 4-induced cutaneous photosensitivity and to evaluate whether such treatment adversely influenced Pc 4 PDT-induced tumor regression. Compared to Photofrin, Pc 4 produced cutaneous photosensitivity that was transient, resolving within 24 h, and that could be elicited for only 10 days after administration. In contrast, Photofrin caused photosensitivity that required 4 days to resolve and could be elicited for at least 1 month after it was administered. The Pc 4-induced cutaneous photosensitivity could be blocked by corticosteroids and an inhibitor of vasoactive amines (cyproheptadine). The TNF-alpha gene transcription was found to increase in keratinocytes following treatment with Pc 4 and light. The anti-TNF-alpha antibodies and pentoxifylline, an inhibitor of cytokine transcription, also prevented cutaneous photosensitivity, implicating TNF-alpha in the pathogenesis of Pc 4-induced cutaneous photosensitivity. None of these agents had any effect on Pc 4 PDT-induced tumor regression. Cyproheptadine, dexamethasone, pentoxifylline and TNF-alpha antibodies may be valuable pharmacologic agents in the management of cutaneous photosensitivity associated with PDT without altering the efficacy of this new therapeutic modality. The findings suggest that it should be possible to devise PDT protocols that block cutaneous photosensitivity without impairing the anti-tumor response to the agents.

Animals↗