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Catherine Sweeney

Publications and source records attributed to Catherine Sweeney.

18 recordsLinked to original sources
PubMed2006

Biomechanical regulation of hedgehog signaling in vascular smooth muscle cells in vitro and in vivo.

Hedgehog (Hh) signaling has recently been shown to be both responsive to mechanical loading in vitro and to control vascular development in vivo. We investigated the role of cyclic strain and pulsatile flow in modulating Hh signaling and growth of adult rat vascular smooth muscle cells (SMC) in culture. Exposure of SMC to defined equibiaxial cyclic strain (0% and 10% stretch, 60 cycles/min, for 24 h) significantly decreased sonic hedgehog (Shh) and patched 1 (Ptc1) expression while concurrently inhibiting Gli(2)-dependent promoter activity and mRNA expression, respectively. Cyclic strain significantly decreased SMC proliferation (cell counts and proliferating cell nuclear antigen expression) concomitant with a marked increase in SMC apoptosis (fluorescence-activated cell sorter analysis, acridine orange staining of apoptotic nuclei and Bax/Bcl-x(L) ratio). These strain-induced changes in proliferation and apoptosis were significantly attenuated following addition of either recombinant Shh (3.5 microg/ml) or overexpression of the Notch 3 intracellular domain (Notch IC). Further studies using a perfused transcapillary culture system demonstrated a significant decrease in Hh signaling in SMC following exposure of cells to increased pulsatile flow concomitant with a decrease in proliferation and an increase in apoptosis. Finally, the pulsatile flow-induced decreases in Hh signaling were validated in vivo following flow-induced rat carotid arterial remodeling after 28 days. These data suggest that Hh expression is diminished by biomechanical stimulation in vitro and in vivo and thus may play a fundamental role in arterial remodeling and atherogenesis in vivo.

Animals↗
PubMed2005

Notch-mediated CBF-1/RBP-J{kappa}-dependent regulation of human vascular smooth muscle cell phenotype in vitro.

Vascular smooth muscle cell (VSMC) phenotypic modulation is a key factor in vascular pathology. We have investigated the role of Notch receptor signaling in controlling human vascular smooth muscle cell (hVSMC) differentiation in vitro and established a role for cyclic strain-induced changes in Notch signaling in promoting this phenotypic response. The expression of alpha-actin, calponin, myosin, and smoothelin was examined by performing immunocytochemistry, Western blot analysis, and quantitative real-time PCR in hVSMCs cultured under static conditions after forced overexpression of constitutively active Notch 1 and 3 receptors, inhibition of endogenous Cp-binding factor 1 (CBF-1)/recombination signal sequence-binding protein-Jkappa (RBP-Jkappa) signaling, and exposure to cyclic strain using a Flexercell Tension Plus unit. Overexpression of constitutively active Notch intracellular (IC) receptors (Notch 1 IC and Notch 3 IC) resulted in a significant downregulation of alpha-actin, calponin, myosin, and smoothelin expression, an effect that was significantly attenuated after inhibition of Notch-mediated, CBF-1/RBP-Jkappa-dependent signaling by coexpression of RPMS-1 (Epstein-Barr virus-encoded gene product) and selective knockdown of basic helix-loop-helix factors [hairy enhancer of split (HES) gene and Hes-related transcription (Hrt) factors Hrt-1, Hrt-2, and Hrt-3] using targeted small interfering RNA. Cells cultured under conditions of defined equibiaxial cyclic strain (10% strain, 60 cycles/min, 24 h) exhibited a significant reduction in Notch 1 IC and Notch 3 IC expression concomitant with a significant increase in VSMC differentiation marker expression. Moreover, this cyclic strain-induced increase was further enhanced after inhibition of CBF-1/RBP-Jkappa-dependent signaling with RPMS-1. These findings suggest that Notch promotes changes in hVSMC phenotype via activation of CBF-1/RBP-Jkappa-dependent pathways in vitro and contributes to the phenotypic response of VSMCs to cyclic strain-induced changes in VSMC differentiation.

Actins↗
PubMed2005

Cyclic strain inhibits Notch receptor signaling in vascular smooth muscle cells in vitro.

Notch signaling has been shown recently to regulate vascular cell fate in adult cells. By applying a uniform equibiaxial cyclic strain to vascular smooth muscle cells (SMCs), we investigated the role of strain in modulating Notch-mediated growth of SMCs in vitro. Rat SMCs cultured under conditions of defined equibiaxial cyclic strain (0% to 15% stretch; 60 cycles/min; 0 to 24 hours) exhibited a significant temporal and force-dependent reduction in Notch 3 receptor expression, concomitant with a significant reduction in Epstein Barr virus latency C promoter-binding factor-1/recombination signal-binding protein of the Jkappa immunoglobulin gene-dependent Notch target gene promoter activity and mRNA levels when compared with unstrained controls. The decrease in Notch signaling was Gi-protein- and mitogen-activated protein kinase-dependent. In parallel cultures, cyclic strain inhibited SMC proliferation (cell number and proliferating cell nuclear antigen expression) while significantly promoting SMC apoptosis (annexin V binding, caspase-3 activity and bax/bcl-x(L) ratio). Notch 3 receptor overexpression significantly reversed the strain-induced changes in SMC proliferation and apoptosis to levels comparable to unstrained control cells, whereas Notch inhibition further potentiated the changes in SMC apoptosis and proliferation. These findings suggest that cyclic strain inhibits SMC growth while enhancing SMC apoptosis, in part, through regulation of Notch receptor and downstream target gene expression.

Animals↗
PubMed2004

Notch 1 and 3 receptor signaling modulates vascular smooth muscle cell growth, apoptosis, and migration via a CBF-1/RBP-Jk dependent pathway.

Vascular smooth muscle cell (SMC) fate decisions (cell growth, migration, and apoptosis) are fundamental features in the pathogenesis of vascular disease. We investigated the role of Notch 1 and 3 receptor signaling in controlling adult SMC fate in vitro by establishing that hairy enhancer of split (hes-1 and -5) and related hrt's (hrt-1, -2, and -3) are direct downstream target genes of Notch 1 and 3 receptors in SMC and identified an essential role for nuclear protein CBF-1/RBP-Jk in their regulation. Constitutive expression of active Notch 1 and 3 receptors (Notch IC) resulted in a significant up-regulation of CBF-1/RBP-Jk-dependent promoter activity and Notch target gene expression concomitant with significant increases in SMC growth while concurrently inhibiting SMC apoptosis and migration. Moreover, inhibition of endogenous Notch mediated CBF-1/RBP-Jk regulated gene expression with a non-DNA binding mutant of CBF-1, a Notch IC deleted of its delta RAM domain and the Epstein-Barr virus encoded RPMS-1, in conjunction with pharmacological inhibitors of Notch IC receptor trafficking (brefeldin A and monensin), resulted in a significant decrease in cell growth while concomitantly increasing SMC apoptosis and migration. These findings suggest that endogenous Notch receptors and downstream target genes control vascular cell fate in vitro. Notch signaling, therefore, represents a novel therapeutic target for disease states in which changes in vascular cell fate occur in vivo.

Animals↗
PubMed2004

The role of neuronal nitric oxide in the vagal control of cardiac interval of the rat heart in vitro.

The aim of this study was to examine the role of neuronal nitric oxide (NO) on vagal regulation of the rat heart in vitro using the neuronal nitric oxide synthase (nNOS) inhibitor 1-(2-trifluoromethylphenyl) imidazole (TRIM). All experiments were carried out in the presence of the beta-adrenoreceptor antagonist atenolol (4 microM). Right thoracic vagus, or its cardiac branch, was stimulated at frequencies of 2, 4, 8, 16 and 32 Hz (pulse duration 1 ms, 20 V, for 20 s) before and after addition of TRIM (0.14 mM) and cardiac interval (ms) assessed. There was a significant positive linear correlation between cardiac interval and vagal frequency giving a slope of 2.76+/-0.8 ms/Hz (slope+/-S.E. slope; data pooled from eight rats) which was significantly attenuated following TRIM to 0.4+/-0.6 ms/Hz (P<0.05 ANOVA; n=8 rats). Nicotine applied in cumulative concentrations (0.03, 0.1, 0.3, 0.5, 1 mM) caused a linear concentration-dependent increase in cardiac interval, with a slope of 403+/-72 ms/mM (n=10 rats) which was significantly attenuated after treatment with hexamethonium (28 microM), to 190+/-36 ms/mM (n=10 rats, P<0.05 ANOVA), and atropine (3 microM) 100+/-31 ms/mM (n=9 rats, P<0.05 ANOVA) but not following TRIM (0.14 mM) 262+/-48 ms/mM (n=9 rats, P<0.05 ANOVA). These results suggest that NO facilitates vagal effects on the rat heart in vitro by an action at the pre-ganglionic/post-ganglionic synapse.

Animals↗
PubMed2004

Methadone versus morphine as a first-line strong opioid for cancer pain: a randomized, double-blind study.

PURPOSE: To compare the effectiveness and side effects of methadone and morphine as first-line treatment with opioids for cancer pain. PATIENTS AND METHODS: Patients in international palliative care clinics with pain requiring initiation of strong opioids were randomly assigned to receive methadone (7.5 mg orally every 12 hours and 5 mg every 4 hours as needed) or morphine (15 mg sustained release every 12 hours and 5 mg every 4 hours as needed). The study duration was 4 weeks. RESULTS: A total of 103 patients were randomly assigned to treatment (49 in the methadone group and 54 in the morphine group). The groups had similar baseline scores for pain, sedation, nausea, confusion, and constipation. Patients receiving methadone had more opioid-related drop-outs (11 of 49; 22%) than those receiving morphine (three of 54; 6%; P =.019). The opioid escalation index at days 14 and 28 was similar between the two groups. More than three fourths of patients in each group reported a 20% or more reduction in pain intensity by day 8. The proportion of patients with a 20% or more improvement in pain at 4 weeks in the methadone group was 0.49 (95% CI, 0.34 to 0.64) and was similar in the morphine group (0.56; 95% CI, 0.41 to 0.70). The rates of patient-reported global benefit were nearly identical to the pain response rates and did not differ between the treatment groups. CONCLUSION: Methadone did not produce superior analgesic efficiency or overall tolerability at 4 weeks compared with morphine as a first-line strong opioid for the treatment of cancer pain.

Administration, Oral↗
PubMed2004

Impact of a half-day multidisciplinary symptom control and palliative care outpatient clinic in a comprehensive cancer center on recommendations, symptom intensity, and patient satisfaction: a retrospective descriptive study.

To characterize a new, one-stop multidisciplinary palliative care (MD) clinic which offers standardized multidisciplinary assessment, specific care recommendations, patient and family education, and on-site counseling, we retrospectively compared the assessments of 138 consecutive patients with advanced cancer referred to the MD clinic and 77 patients referred to a traditional pain and symptom management (PSM) clinic. The two groups were similar in tumor type, demographics, and symptom distress. The MD clinic team (physicians; nurses; pharmacists; physical, speech, and occupational therapists; social workers; chaplains; nutritionists; psychiatric nurse practitioner) delivered 1,066 non-physician recommendations (median 4 per patient, range 0-37). The PSM clinic team made no non-physician recommendations, but referred 14 patients to other medical specialists. In 80 (58%) MD-clinic patients with follow-up 9 days (median) after assessment, significant improvement was observed in pain, nausea, depression, anxiety, sleep, dyspnea, and well-being, but not in fatigue, anorexia, or drowsiness. In 83 patients interviewed after the MD clinic, satisfaction was rated as excellent (5 out of 5) in 86-97% of seven areas. Assessment at an MD clinic results in a high number of patient care recommendations, improved symptoms, and high levels of patient satisfaction.

Adolescent↗
PubMed2004

Potent analgesics are more expensive for patients in developing countries: a comparative study.

Opioids are some of the most important analgesic medications for the management of both moderate to severe pain and several are included on the World Health organization (WHO) list of essential drugs. Opioid costs in developing countries have been reported to be higher than those in developed nations. This study documents retail prices and availability of several potent opioids in a number of developing and developed countries. Pain and Palliative Care specialists currently working in their countries were asked to collect data on the retail cost of a 30 day supply of 15 different opioid preparations in 5 developing and 7 developed countries. Data were analyzed to compare costs and costs as a percentage of gross national product (GNP) per capita per month. Opioid costs and availability varied widely in both developing and developed countries. Forty five of 75 opioid preparations were available in developing countries (40% of medications studied were not available) and 76 of 105 preparations were available in the developed countries (28% not available). In US dollars, the median cost of opioids differed between developed and developing countries ($53 and $112 respectively) The median costs of all opioid preparations as a percentage of GNP per capita per month were 36% for developing and 3% for developed nations; the difference was statistically significant (p < 0.001). In developing countries 23 of 45 (51%) of opioid dosage forms cost more than 30% of the monthly GNP per capita, versus only three of 76 (4%) in developed countries. The relative cost of opioids to income is higher in developing countries. Our data suggest that in developing countries opioid access for the majority of patients is likely to be limited by cost, and development of palliative care programs will require heavy or total subsidization of opioid costs.

Analgesics, Opioid↗
PubMed2003

Breast cancer patient perception of the helpfulness of a prompt sheet versus a general information sheet during outpatient consultation: a randomized, controlled trial.

The purpose of this study was to determine the helpfulness of a prompt sheet versus a general information sheet for patient communication with physicians. Sixty women with breast cancer attending their first outpatient consultation with a breast medical oncologist were randomized to receive either a prompt sheet (PS) or a general information (GI) sheet regarding breast cancer. Analysis of the results found that helpfulness of the written material was rated higher in the PS group (8.5 +/- 2) than the GI group (6.2 +/- 3.6), P = 0.005. The mean score of helpfulness in communicating with physicians was 7.9 +/- 2.4 and 5.7 +/- 3.8, respectively, P = 0.01. There were no significant differences between the groups in the average total number of questions asked by the patients or average physician or patient speaking time. We conclude that a disease-specific prompt sheet provided before medical encounters may assist in communication between patients and physicians.

Adult↗
PubMed2003

Place of death of Houston area residents with cancer over a two-year period.

The majority of cancer patients wish to die at home. Improved understanding of place of death and its relevant demographic predictors is important for the planning of palliative cancer care programs. The purpose of this study was to determine the place and predictors of site of death in cancer patients in a major U.S. metropolitan area. Death certificate data over two years were analyzed for Houston area residents with cancer who died in the Houston area. Information was obtained on factors that might be associated with the place where cancer patients die. For the purpose of this study, we looked at the following variables: primary site of cancer (hematological, breast, genitourinary, gastrointestinal, lung, and other); black, white, Hispanic, or Asian; age at death; marital status; sex; whether or not veteran of U.S. armed forces; levels of education; and area of residency within the Houston area. Univariate and multivariate analyses were performed. The majority of patients died in the hospital (51-52% both years), with the next most frequently occurring group dying at home (34-35% both years). Stepwise multivariate analysis resulted in a 6-variable logistic regression model. In this model, the odds of dying in hospital were increased by a factor of 2.7 if the patient had a hematological cancer (P<0.0001), a factor of 1.6 if the patient lived in Harris County (P<0.0001), and a factor of 1.5 if the patient was black (P<0.0001). Further characterization of factors associated with increased risk of hospital death rate is needed and systems should be developed to enable the majority of cancer patients to access palliative care services in the multiple settings in which they die.

Aged↗
PubMed2003

Perception of discomfort by relatives and nurses in unresponsive terminally ill patients with cancer: a prospective study.

Perception of discomfort in dying patients is a risk factor for distress and bereavement among relatives. This study determined the perception of discomfort, the frequency of observed behaviors, and their association among relatives and among nurses who care for unresponsive dying patients. Sixty unresponsive dying patients' relatives and their nurses were asked to evaluate patient discomfort levels, the frequencies of six observed behaviors, and the suspected reasons for the patient discomfort. The mean levels of perceived discomfort were similar, but the association was poor between the relatives and the nurses. Relatives reported significantly more observed behaviors and associated more pain as a reason for patient discomfort than did nurses. The findings suggest that relatives are intensely attuned to their loved ones' conditions and reactions, and nurses' responses are fairly similar. Further research is warranted, however, to distinguish between the distress that the relatives perceive and the actual suffering of patients.

Adult↗
PubMed2003

A randomized controlled trial of supplemental oxygen versus air in cancer patients with dyspnea.

CONTEXT: The symptomatic benefits of oxygen in patients with cancer who have nonhypoxic dyspnea are not well defined. OBJECTIVE: To determine whether or not oxygen is more effective than air in decreasing dyspnea and fatigue and increasing distance walked during a 6-minute walk test. PATIENTS AND METHODS: Patients with advanced cancer who had no severe hypoxemia (i.e., had an O2 saturation level of > or = 90%) at rest and had a dyspnea intensity of > or = 3 on a scale of 0-10 (0 = no shortness of breath, 10 = worst imaginable shortness of breath) were recruited from an outpatient thoracic clinic at a comprehensive cancer center. This was a double-blind, randomized crossover trial. Supplemental oxygen or air (5 L/min) was administered via nasal cannula during a 6-minute walk test. The outcome measures were dyspnea at 3 and 6 minutes, fatigue at 6 minutes, and distance walked. We also measured oxygen saturation levels at baseline, before second treatment phase, and at the end of study. RESULTS: In 33 evaluable patients (31 with lung cancer), no significant differences between treatment groups were observed in dyspnea, fatigue, or distance walked (dyspnea at 3 minutes: P = 0.61; dyspnea, fatigue, and distance walked at 6 minutes: P = 0.81, 0.37, and 0.23, respectively). CONCLUSIONS: Currently, the routine use of supplemental oxygen for dyspnea during exercise in this patient population cannot be recommended.

Adult↗
PubMed2002

Place of death and its predictors for local patients registered at a comprehensive cancer center.

PURPOSE: To help with planning of a palliative care program, we reviewed the place of death of patients who were registered at our comprehensive cancer center and explored factors that predicted death in the hospital versus death at home. PATIENTS AND METHODS: A retrospective study was undertaken of local patients who were registered at the University of Texas M.D. Anderson Cancer Center and died during the 1997/1998 fiscal year. Data from the institutional tumor registry and from the State of Texas Bureau of Vital Statistics file were collected and analyzed. The main outcome measures were place of death, patient characteristics associated with place of death, and time from registration at the institution to death. RESULTS: Of 1,793 local patients, 251 (14%) died at M.D. Anderson Cancer Center; the remaining 86% died elsewhere. A total of 617 (34%) died at home, and 929 (52%) died in an acute hospital setting (including M.D. Anderson). A total of 1,040 (58%) died within 2 years of registration. The risk of hospital death versus home death increased for patients with cancer at a hematologic site (odds ratio [OR], 4.4; 95% confidence interval [CI], 2.8 to 6.8) and black ethnicity (OR, 1.9; 95% CI, 1.4 to 2.6) and decreased for patients who paid with Medicare (OR, 0.71; 95% CI, 0.57 to 0.90). CONCLUSION: Most patients died in an acute care hospital setting and within 2 years of registration. Our data show some predictors of hospital death for cancer patients and suggest that better hospital palliative care services and integrated palliative care systems that bridge community and acute hospitals are needed.

Cancer Care Facilities↗
PubMed2002

Methadone use in cancer patients with pain: a review.

In recent years a better understanding of the pharmacologic and pharmacokinetic properties of methadone, including equianalgesic ratios has led to its increased use as a second line opioid for the treatment of pain in patients with cancer. Methadone may be an important alternative for those who have side effects related to the use of other opioids because it has no known active metabolites, is well absorbed by oral and rectal routes, and also has the advantage of very low cost. However, it has a long, unpredictable half-life, which can result in accumulation and toxicity in some patients. In addition, rotation to methadone as a second line agent is more complex than with other opioids because of its increased potency in those patients who are opioid tolerant, particularly those who have been on higher doses of other opioids. Future research should address the use of methadone as a first-line agent in the management of cancer pain, its use in patients with neuropathic pain, and in those who develop rapid tolerance to other opioids. In some patients with cancer the long half-life of methadone offers the advantage of extended dosing intervals to 12 and even 24 hours, further research is also needed in this area.

Analgesics, Opioid↗
PubMed2002

Palliative care models: international perspective.

The delivery of palliative care can vary greatly between countries depending on socioeconomic conditions and cultural issues. The evolution and development of palliative care varies greatly and influences the development of palliative care models. Models of palliative care in three different countries are discussed and suggestions are made for the future development of palliative care in developing and developed countries.

Argentina↗