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C Rogers

Publications and source records attributed to C Rogers.

At least 37 records · Page 2Linked to original sources
PubMed2001

Dependence of 13C NMR chemical shifts on conformations of rna nucleosides and nucleotides.

Cross-polarization magic-angle spinning solid-state NMR spectroscopy has been used to investigate the dependence of (13)C sugar chemical shifts on specific conformational parameters of a variety of ribonucleotides and ribonucleosides. Solid-state NMR is a valuable tool for nucleoside and nucleotide structural studies since it provides the means to acquire spectra that correspond to single conformations, as opposed to (13)C solution NMR methods. The distinct effects of sugar puckering on the C1', C4', and C5' resonances of C2' endo (S type) and C3' endo (N type) furanoid conformations allow us to separate them into two groups. Further analysis of each group reveals an additional dependence of the C1' and C5' resonances on the glycosidic and C4'-C5' exocyclic torsion angles, respectively. However, it is found that the glycosidic conformation cannot independently be determined from sugar (13)C chemical shift data. The statistical methods of exploratory data analysis and discriminant analysis are used to construct two canonical coordinates-linear combinations of chemical shifts which give the statistically optimal determination of the conformation from the NMR data.

Carbohydrate Conformation↗
PubMed2001

Factors associated with sudden death of individuals requiring restraint for excited delirium.

The purpose of this article is to identify and rank factors associated with sudden death of individuals requiring restraint for excited delirium. Eighteen cases of such deaths witnessed by emergency medical service (EMS) personnel are reported. The 18 cases reported were restrained with the wrists and ankles bound and attached behind the back. This restraint technique was also used for all 196 surviving excited delirium victims encountered during the study period. Unique to these data is a description of the initial cardiopulmonary arrest rhythm in 72% of the sudden death cases. Associated with all sudden death cases was struggle by the victim with forced restraint and cessation of struggling with labored or agonal breathing immediately before cardiopulmonary arrest. Also associated was stimulant drug use (78%), chronic disease (56%), and obesity (56%). The primary cardiac arrest rhythm of ventricular tachycardia was found in 1 of 13 victims with confirmed initial cardiac rhythms, with none found in ventricular fibrillation. Our findings indicate that unexpected sudden death when excited delirium victims are restrained in the out-of-hospital setting is not infrequent and can be associated with multiple predictable but usually uncontrollable factors.

Adult↗
PubMed2001

The role of symptomatic colds in asthma exacerbations: Influence of outdoor allergens and air pollutants.

BACKGROUND: Both air pollutants and respiratory viral infections have been recognized to be important triggers of asthma exacerbations, but the possible interaction of these has not been assessed in an epidemiologic study. OBJECTIVE: In this study, we aimed to assess the possible associations of symptomatic colds with outdoor allergens and air pollutants in exacerbating asthma. METHODS: A total of 57 adults and children with asthma participated in a 1-year study in Vancouver, British Columbia. Diary cards recording symptoms of asthma and colds, medication usage, and peak expiratory flow rates were completed twice daily. Outdoor air pollutant levels and levels of pollen and fungal spores were measured. Levels were examined for associations with exacerbations of asthma with symptoms of a cold, as compared with asthma exacerbations with no cold symptoms and colds in the absence of asthma exacerbations. RESULTS: Of 130 asthma exacerbations, 47% were associated with cold symptoms (accounting for 44% of episodes of colds). Asthma exacerbations with colds were associated with higher levels of sulfur dioxide, and nitric oxide during March to November in comparison with asthma exacerbations without cold symptoms (P <.018). Cold-symptom days overall were more common in winter and were significantly associated with lower temperatures, lower ozone levels, and higher sulfur dioxide, nitrogen dioxide, nitrogen oxide (NO and NO(x)), and carbon monoxide levels. CONCLUSIONS: Asthma exacerbations are commonly associated with cold symptoms. These episodes are associated with higher levels of sulfur dioxide and nitrogen oxides from March to November in comparison with asthma exacerbations without cold symptoms.

Adolescent↗
PubMed2001

Achieving safer sex with choice: studying a women's sexual risk reduction hierarchy in an STD clinic.

A flexible, risk-reduction approach, as compared with a single method approach, may increase sexually transmitted disease (STD)/HIV protection for women attending STD clinics. A brief intervention was tested in an observational study of 292 STD clinic patients in three distinct cohorts. These included subjects counseled on (1) the "women's safer sex hierarchy of prevention methods" (hierarchy cohort, n = 118), including the female condom (FC), male condom (MC), diaphragm, cervical cap, and spermicides, (2) MC only (n = 62), or (3) FC (n = 112) only. We evaluate method use and level of protection achieved at 6-month follow-up among the women in the hierarchy cohort and compare the level of unprotected sex across the three cohorts, using ordinal logistic regression analyses and an imputation procedure to account for attrition. In the hierarchy cohort, the MC, FC, spermicidal film, foam, suppository, and diaphragm were used with main partners by 80%,46%, 37%, 28%, 17%, and 5% of women, respectively. Spermicides were used frequently, mainly in conjunction with condoms. As compared with hierarchy subjects, both MC cohort subjects (OR = 2.3, p = 0.01) and FC cohort subjects (OR = 1.6, p = 0.11) were more likely to report 100% unprotected sex. The tendency for subjects to move toward higher levels of protection was observed most strongly in the hierarchy group. Hierarchical-type counseling, compared with single method counseling, leads to increased protection during sex among women at high risk of STD/HIV infection and should be implemented in STD clinics.

Adult↗
PubMed2001

Rheolytic thrombectomy for in-stent thrombosis: creating a diagnostic window.

Acute-stent thrombosis is a relatively uncommon complication of coronary artery stenting, however, it is a potentially catastrophic event. In this case report of stent thrombosis, rheolytic thrombectomy is used to reestablished flow within the artery and, thereby, facilitate intravascular ultrasound. This documented that inadequate stent expansion, residual disease, and tissue prolapse through the stent at an angulated segment of the artery are factors that may underlie thrombosis. This case illustrates that rheolytic thrombectomy is feasible in subacute thrombosis, and that this approach facilitates diagnostic evaluation and treatment of underlying factors involved in stent thrombosis.

Aged↗
PubMed2001

Results from 10 years of breast screening in Wales.

OBJECTIVE: To present results from 10 years of breast screening in Wales, including rates of interval cancers. SETTING: All women aged 50-64 years in Wales; approximately 250,000 in each screening round. METHODS: Breast Test Wales (BTW) began mammographic screening in 1989 as part of the National Breast Screening Programme. Two view mammography was introduced at the inception of the Welsh programme for all prevalent screens. Single view mammography was subsequently performed for incident screens. Interval cancers were identified by matching details from the BTW administrative screening database with the BTW database of all incident breast cancers for residents in Wales. RESULTS: For the first and second round prevalent screens, the cancer detection rate was 8.6 per 1000 and 7.4 per 1000 screened, respectively. The interval cancer rates following round one were 4.9 per 10,000 in the first 12 months, 9.0 per 10,000 between 12 and 24 months, and 11.6 per 10,000 between 24 and 36 months after screening. For the second round incident screens the detection rate was 4.6 per 1000 and the standardised detection ratio was 0.89, but the interval cancer rates in the first year after incident screens were not statistically different from those following prevalent screens. There was no change in the proportion of invasive breast cancers which were < 15 mm in diameter, or in the grades of invasive cancer between the first and second rounds, prevalent or incident screens. CONCLUSIONS: Breast Test Wales has achieved the standards set by the National Health Service Breast Screening Programme. Taking two views at the prevalent screen gave high sensitivity and may have resulted in the low standardised detection ratio at subsequent incident screens.

Breast Neoplasms↗
PubMed2001

Photodynamic therapy with motexafin lutetium induces redox-sensitive apoptosis of vascular cells.

Motexafin lutetium is a photosensitizer that accumulates in atherosclerotic plaque and, after activation by far-red light, produces cytotoxic singlet oxygen. The combination of photosensitizer and illumination, known as photodynamic therapy (PDT), has been shown to reduce atheroma formation in animal models and is under clinical investigation. However, the effects of PDT with motexafin lutetium on isolated vascular cells are unknown. This study was designed to characterize the effects of PDT on vascular cell viability and to define the cell-death pathway for this agent. Fluorescence microscopy of RAW macrophages and human vascular smooth muscle cells revealed time-dependent uptake of motexafin lutetium. Illumination of motexafin lutetium-loaded cells with 732-nm light (2 J/cm(2)) impaired cellular viability and growth (IC(50) 5 to 20 micromol/L). Depletion of intracellular glutathione potentiated (P=0.035) and the addition of antioxidant N-acetylcysteine attenuated (P=0.002) cell death, suggesting that the intracellular redox state influences motexafin lutetium action. PDT was associated with the loss of mitochondrial membrane potential, mitochondrial release of cytochrome c, and caspase activation. PDT promoted phosphatidylserine externalization and induced apoptotic DNA fragmentation, with the number of apoptotic cells increasing from 7+/-2% to 34+/-3% of total cells. Reducing plaque cellularity by the induction of apoptosis may be one mechanism by which PDT reduces plaque burden, possibly modulates plaque vulnerability, and inhibits restenosis in vivo.

Animals↗
PubMed2001

The Peritraumatic Distress Inventory: a proposed measure of PTSD criterion A2.

OBJECTIVE: Meeting criterion A2 for the diagnosis of posttraumatic stress disorder (PTSD) in DSM-IV requires that an individual have high levels of distress during or after the traumatic event. Because of the paucity of valid and reliable instruments for assessing such responses, the authors developed a 13-item self-report measure, the Peritraumatic Distress Inventory, to obtain a quantitative measure of the level of distress experienced during and immediately after a traumatic event. METHOD: The cross-sectional study group comprised 702 police officers and 301 matched nonpolice comparison subjects varying in ethnicity and gender who were exposed to a wide range of critical incidents. RESULTS: The Peritraumatic Distress Inventory was found to be internally consistent, with good test-retest reliability and good convergent and divergent validity. Even after controlling for peritraumatic dissociation and for general psychopathology, the authors found that Peritraumatic Distress Inventory scores correlated with two measures of posttraumatic stress symptoms. CONCLUSIONS: The Peritraumatic Distress Inventory holds promise as a measure of PTSD criterion A2. Future studies should prospectively examine the ability of the Peritraumatic Distress Inventory to predict PTSD and its associated biological and cognitive correlates in other trauma-exposed groups.

Adult↗
PubMed2001

Percutaneous coronary intervention and subsequent endovascular beta-radiation brachytherapy in a 14-year-old with repaired anomalous left coronary artery from pulmonary artery.

Anomalous origin of the left coronary artery from pulmonary artery (ALCAPA) is a rare congenital anomaly. Re-establishment of the dual coronary system is the standard treatment, although the long-term outcome after surgical repair is not well defined. We report a case in which coronary stenting was performed to treat left anterior descending artery lesions eight months after surgical repair of ALCAPA. The patient then developed rapid in-stent restenosis within three months, which was successfully treated by rotational atherectomy, balloon angioplasty, and catheter-based beta-radiation brachytherapy. Follow-up angiograms after three and six months showed no recurrent in-stent restenosis. This represents the first report of coronary stenting in the setting of ALCAPA, and the first report of catheter-based intracoronary radiation therapy in a pediatric patient.

Adolescent↗
PubMed2001

Topical and systemic therapies for the aging face.

Many cosmeseuticals and drugs are available to treat and augment therapy for the aging face. Patients frequently have misconceptions about the use of these agents, and it is important that today's cosmetic surgeon know how to maximize the benefits while minimizing side effects. The role of retinoids, antioxidants, hydroxy acids, bleaching agents, moisturizers, and sunscreens are reviewed as they relate to skin rejuvenation.

Adenine↗
PubMed2001

Development of a protocol for evaluation of mammographic surveillance services in women under 50 with a family history of breast cancer.

BACKGROUND: Preliminary retrospective data suggest it is possible to identify impalpable breast cancer in women presenting with a family history of breast cancer under the age of 50, by using regular mammography. In consequence, this service is offered in a number of centres in the UK. The effectiveness of such a service, however, has not been fully evaluated. METHODS: We propose to perform such an evaluation in a cohort of 20000 women under the age of 50 with a significant family history of breast cancer, given regular mammographic surveillance over 5 years. Comparison of surgical and pathological data with completed and ongoing population screening trials using analysis techniques of varying complexity will be performed to obtain an accurate prediction of future breast-cancer mortality reduction. The formal aims are: i) to estimate the difference in breast-cancer mortality in women under the age of 50 with a significant family history of breast cancer having regular mammography, compared with those not being screened; ii) to estimate the cost-effectiveness of regular mammography in this group of women, compared with no screening. The increase in health service resource use attributable to such a policy will be compared with no screening, and costed. Incremental cost-effectiveness ratios of implementing the standardised mammography strategy compared with no screening will be presented in terms of the additional cost per cancer detected, per life saved and per life-year saved.

Adult↗
PubMed2000

The comparative pathobiology of atherosclerosis and restenosis.

Percutaneous coronary interventions (PCIs) play an increasingly important role in the management of patients with coronary artery disease. However, these important procedures are complicated by restenosis in a sizeable number of patients. The pathobiology of atherosclerosis comprises a complex interaction among lipids, the endothelium, circulating and tissue inflammatory cells, platelets, and vascular smooth muscle cells. The superimposition of the mechanical and cellular consequences of PCIs on the abnormal substrate of atherosclerosis leads to a characteristic and distinct pathobiology that initiates and perpetuates restenosis. A clear understanding of the significant differences between atherosclerosis and restenosis will provide a rational basis for developing treatment plans that always address both problems. This article reviews and contrasts the pathobiology of atherosclerosis and restenosis and compares the mechanisms and time-course of these distinct entities.

Animals↗
PubMed2000

Randomized trial of a specialist genetic assessment service for familial breast cancer.

BACKGROUND: Because of the growing demand for genetic assessment, there is an urgent need for information about what services are appropriate for women with a family history of breast cancer. Our purpose was to compare the psychologic impact and costs of a multidisciplinary genetic and surgical assessment service with those of current service provisions. METHODS: We carried out a prospective randomized trial of surgical consultation with (the trial group) and without (the control group) genetic assessment in 1000 women with a family history of breast cancer. All P: values are from two-sided tests. RESULTS: Although statistically significantly greater improvement in knowledge about breast cancer was found in the trial group (P: =.05), differences between groups in other psychologic outcomes were not statistically significant. Women in both groups experienced statistically significant reductions in anxiety and found attending the clinics to be highly satisfying. An initial specialist genetic assessment cost pound 14.27 (U.S. $22.55) more than a consultation with a breast surgeon. Counseling and genetic testing of affected relatives, plus subsequent testing of family members of affected relatives identified as mutation carriers, raised the total extra direct and indirect costs per woman in the trial group to pound 60.98 (U.S. $96.35) over costs for the control subjects. CONCLUSIONS: There may be little benefit in providing specialist genetics services to all women with a family history of breast cancer. Further investigation of factors that may mediate the impact of genetic assessment is in progress and may reveal subgroups of women who would benefit from specialist genetics services.

Adult↗
PubMed2000

A randomized trial of hierarchical counseling in a short, clinic-based intervention to reduce the risk of sexually transmitted diseases in women.

INTRODUCTION: Effective public health interventions to reduce the incidence of sexually transmitted disease (STD), including HIV, among women are urgently needed. METHODS: A randomized trial among STD clinic patients of two types of counseling regarding methods to reduce disease transmission: a 'hierarchical' message (HP), with counseling on male condoms, female condoms, diaphragms, cervical caps, and spermicides (three formulations) and a single method message (SM) covering male condoms only or female condoms only. For this analysis, 1591 subjects received one of three educational messages at the central public STD clinic in Philadelphia. Disease incidence data for up to 6 months following the index visit were extracted from the clinic's electronic database. The primary outcome was STD reinfection: laboratory-confirmed trichomonas infection and/or clinical diagnoses of at least one of four STD. Rates were based on the full sample of randomized women (full sample) and on the subset who spontaneously returned between 22 days and 183 days following their initial visit (returners). RESULTS: Rates of trichomonas infection (SM 2.5% full sample and 12.9% returners versus HP 2.4% full sample and 11.5% returners) and clinical diagnoses (SM 6.3% full sample and 39.7% returners versus HP 6.9% full sample and 41.2% returners) did not differ across the two arms of the randomized trial, both as a straight percentage and in survival analysis (P = .81). CONCLUSION: At least in this single-session intervention trial, increasing choices in protection for women did not produce a change in disease risk compared with single-method approaches.

Adult↗
PubMed2000

Randomised controlled trial of nurse practitioner versus general practitioner care for patients requesting "same day" consultations in primary care.

OBJECTIVE: To ascertain any differences between care from nurse practitioners and that from general practitioners for patients seeking "same day" consultations in primary care. DESIGN: Randomised controlled trial with patients allocated by one of two randomisation schemes (by day or within day). SETTING: 10 general practices in south Wales and south west England. SUBJECTS: 1368 patients requesting same day consultations. MAIN OUTCOME MEASURES: Patient satisfaction, resolution of symptoms and concerns, care provided (prescriptions, investigations, referrals, recall, and length of consultation), information provided to patients, and patients' intentions for seeking care in the future. RESULTS: Generally patients consulting nurse practitioners were significantly more satisfied with their care, although for adults this difference was not observed in all practices. For children, the mean difference between general and nurse practitioner in percentage satisfaction score was -4.8 (95% confidence interval -6.8 to -2.8), and for adults the differences ranged from -8.8 (-13.6 to -3.9) to 3.8 (-3.3 to 10.8) across the practices. Resolution of symptoms and concerns did not differ between the two groups (odds ratio 1.2 (95% confidence interval 0.8 to 1.8) for symptoms and 1.03 (0.8 to 1.4) for concerns). The number of prescriptions issued, investigations ordered, referrals to secondary care, and reattendances were similar between the two groups. However, patients managed by nurse practitioners reported receiving significantly more information about their illnesses and, in all but one practice, their consultations were significantly longer. CONCLUSION: This study supports the wider acceptance of the role of nurse practitioners in providing care to patients requesting same day consultations.

Acute Disease↗