Unexposed Patients (unexposed + patient)

Distribution by Scientific Domains


Selected Abstracts


Skin testing in patients with hypersensitivity reactions to iodinated contrast media , a European multicenter study

ALLERGY, Issue 2 2009
K. Brockow
Background:, Iodinated contrast media cause both immediate and nonimmediate hypersensitivity reactions. The aim of this prospective study was to determine the specificity and sensitivity of skin tests in patients who have experienced such reactions. Methods:, Skin prick, intradermal and patch tests with a series of contrast media were conducted in 220 patients with either immediate or nonimmediate reaction. Positive skin tests were defined according to internationally accepted guidelines. Seventy-one never-exposed subjects and 11 subjects who had tolerated contrast medium exposure, served as negative controls. Results:, Skin test specificity was 96,100%. For tests conducted within the time period from 2 to 6 months after the reaction, up to 50% of immediate reactors and up to 47% of nonimmediate reactors were skin test positive. For immediate reactors, the intradermal tests were the most sensitive, whereas delayed intradermal tests in combination with patch tests were needed for optimal sensitivity in nonimmediate reactors. Contrast medium cross-reactivity was more common in the nonimmediate than in the immediate group. Interestingly, 49% of immediate and 52% of nonimmediate symptoms occurred in previously unexposed patients. Many of these patients were skin test positive, indicating that they were already sensitized at the time of first contrast medium exposure. Conclusions:, These data suggest that at least 50% of hypersensitivity reactions to contrast media are caused by an immunological mechanism. Skin testing appears to be a useful tool for diagnosis of contrast medium allergy and may play an important role in selection of a safe product in previous reactors. [source]


Parkinsonism in patients with a history of amphetamine exposure

MOVEMENT DISORDERS, Issue 2 2010
Chadwick W. Christine MD
Abstract We recently found a higher rate of prolonged amphetamine exposure in patients diagnosed with Parkinson's disease (PD) than in spouse/caregiver controls. Since distinguishing features have been described in some patients with parkinsonism due to environment exposures (e.g., manganese), we sought to compare the clinical features of patients with PD with prolonged amphetamine exposure with unexposed patients with PD. Prolonged exposure was defined as a minimum of twice a week for ,3 months, or weekly use ,1 year. We reviewed the clinical records of patients with PD who had participated in a telephone survey of drug and environmental exposures and compared the clinical features of patients with a history of prolonged amphetamine exposure to patients who had no such exposure. Records were available for 16 of 17 (94%) patients with prior amphetamine exposure and 127 of 137 (92%) of those unexposed. Age at diagnosis was younger in the amphetamine-exposed group (49.8 ± 8.2 years vs. 53.1 ± 7.4 years; P < 0.05), but other features, including presenting symptoms, initial and later treatments, development of motor fluctuations, and MRI findings were similar between these groups. Because we did not detect clinical features that differentiate parkinsonism in patients with prolonged amphetamine exposure, research to determine whether amphetamine exposure is a risk factor for parkinsonism will require detailed histories of medication and recreational drug use. © 2009 Movement Disorder Society [source]


Use and adherence to beta-blockers for secondary prevention of myocardial infarction: who is not getting the treatment?,

PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 11 2004
Li Wei
Abstract Purpose To characterise those who receive beta-blocker therapy after MI and to estimate the effect of adherence to beta-blocker use on subsequent mortality and recurrent MI. Methods A community-based observational cohort study was done using a record linkage database. Patients were those discharged from hospitals after their first MI between January 1994 and December 1995 and who also survived for at least 1 year. The outcome was all cause mortality and recurrent MI. Results were adjusted for age, sex, social deprivation, airways disease, peripheral vascular disease (PVD), diabetes mellitus, cardiovascular drug use, steroid use and hospitalisation for cardiovascular disease using a logistic regression model and a Cox regression model. Results A total of 865 patients were included in this study. 386 (44.6%) were on beta-blocker treatment during the year after MI. Beta-blocker use was lower amongst high-risk patients (older patients, patients with obstructive airway disease, PVD and those with a previous hospitalisation for heart failure). Mortality was lower in patients treated with beta-blockers compared with those untreated. Good adherence (,80%) was associated with a lower adjusted relative risk of mortality compared with unexposed patients (0.49, 95%CI 0.30,0.80, p,<,0.01). Within the high-risk subgroup of patients, the adjusted relative risk of mortality with good adherence was 0.40 (0.17,0.93, p,=,0.03). Conclusions Beta-blocker use was lower in older patients, patients with airways disease, PVD and heart failure, but these patients appeared to have the greatest benefit from beta-blockers. Good adherence to beta-blocker treatment after MI was associated with a lower risk of mortality. Copyright © 2004 John Wiley & Sons, Ltd. [source]


Salmonella or Campylobacter gastroenteritis prior to a cancer diagnosis does not aggravate the prognosis: a population-based follow-up study

APMIS, Issue 2 2010
KIM O. GRADEL
Gradel KO, Nørgaard M, Schønheyder HC, Dethlefsen C, Ejlertsen T, Kristensen B, Nielsen H. Salmonella or Campylobacter gastroenteritis prior to a cancer diagnosis does not aggravate the prognosis: a population-based follow-up study. APMIS 2010; 118: 136,42. We hypothesized that preceding zoonotic Salmonella or Campylobacter gastroenteritis aggravated the prognosis in cancer patients. Exposed patients comprised all of those diagnosed with first-time Salmonella/Campylobacter gastroenteritis from 1991 and with first-time cancer diagnosis thereafter (through 2003) in two Danish counties. These patients were matched for main cancer type, gender, age and calendar period to unexposed cancer patients, i.e. those without Salmonella/Campylobacter gastroenteritis. We compared cancer stage by age- and comorbidity-adjusted logistic regression analysis, survival by comorbidity-adjusted Cox's regression analysis and mortality dependent on the time period between Salmonella/Campylobacter gastroenteritis and cancer by spline regression curves. The study cohort comprised 272 Salmonella/Campylobacter -exposed cancer patients and 2681 unexposed cancer patients. Prevalence odds ratios [95% confidence intervals (CI)] in exposed as compared with unexposed patients were 0.96 (0.74,1.25) for localized tumours, 1.15 (0.87,1.54) for regional spread and 1.14 (0.84,1.55) for metastases. Adjusted mortality rate ratios (95% CI) were 0.93 (0.75,1.16) for 0,1 year, 1.08 (0.84,1.39) for 2,5 years and 1.02 (0.60,1.73) for the remaining period. Mortality estimates did not change in relation to the time period between gastroenteritis and cancer. Salmonella/Campylobacter gastroenteritis prior to cancer was associated with neither the cancer stage nor a poorer prognosis. [source]