Radiation-induced red cell damage: role of reactive oxygen species

BACKGROUND: Cellular blood components are irradiated to prevent graft- versus-host disease in transfusion recipients at risk for this syndrome. Because gamma radiation can result in the production of reactive oxygen species, the role of reactive oxygen species was investigated in radiation-induced red cell damage. STUDY DESIGN AND METHODS: Whole blood from normal donors was exposed to various doses of t-butyl hydroperoxide (0-1 mM) and/or to gamma-radiation (0-50 Gy). Oxidative damage was assessed by the extent of lipid peroxidation (measured by thiobarbituric acid-reactive substances [TBARS]) and hemoglobin oxidation. Fresh blood was divided into three parts-one initially irradiated and stored, another stored with portions irradiated weekly, and a third stored without irradiation. TBARS and hemoglobin oxidation were measured weekly. RESULTS: As expected, t- butyl hydroperoxide induced TBARS formation and hemoglobin oxidation in a dose-dependent fashion. The gamma-radiation not only increased hemoglobin oxidation and TBARS formation, but also enhanced the t-butyl hydroperoxide effect on red cells. Red cell storage increased TBARS generation and hemoglobin oxidation in a time-dependent fashion. When radiation was administered either initially or after weekly storage, TBARS production and hemoglobin oxidation were increased over that measured in unirradiated paired controls. CONCLUSION: Gamma radiation at clinically used doses increases lipid peroxidation and hemoglobin oxidation in human red cells. The effect of gamma-radiation is accentuated by blood storage and induces damage independent of time of storage.     

Characterization of 107 genomic DNA reference materials for CYP2D6, CYP2C19, CYP2C9, VKORC1, and UGT1A1: a GeT-RM and Association for Molecular Pathology collaborative project

Pharmacogenetic testing is becoming more common; however, very few quality control and other reference materials that cover alleles commonly included in such assays are currently available. To address these needs, the Centers for Disease Control and Prevention's Genetic Testing Reference Material Coordination Program, in collaboration with members of the pharmacogenetic testing community and the Coriell Cell Repositories, have characterized a panel of 107 genomic DNA reference materials for five loci (CYP2D6, CYP2C19, CYP2C9, VKORC1, and UGT1A1) that are commonly included in pharmacogenetic testing panels and proficiency testing surveys. Genomic DNA from publicly available cell lines was sent to volunteer laboratories for genotyping. Each sample was tested in three to six laboratories using a variety of commercially available or laboratory-developed platforms. The results were consistent among laboratories, with differences in allele assignments largely related to the manufacturer's assay design and variable nomenclature, especially for CYP2D6. The alleles included in the assay platforms varied, but most were identified in the set of 107 DNA samples. Nine additional pharmacogenetic loci (CYP4F2, EPHX1, ABCB1, HLAB, KIF6, CYP3A4, CYP3A5, TPMT, and DPD) were also tested. These samples are publicly available from Coriell and will be useful for quality assurance, proficiency testing, test development, and research.     

Left Ventricular Systolic Dysfunction and Cardiovascular Outcomes in Tetralogy of Fallot: Systematic Review and Meta-analysis

BackgroundAlthough there are robust data about the pathophysiology and prognostic implications of left ventricular (LV) systolic dysfunction in patients with acquired heart disease, similar prognostic data about LV systolic dysfunction are sparse in the tetralogy of Fallot (TOF) population. The purpose of this study was to perform a meta-analysis of all studies that assessed the relationship between LV ejection fraction (LVEF) and cardiovascular adverse events (CAEs) defined as death, aborted sudden death, or sustained ventricular tachycardia.MethodsWe used random-effects models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).ResultsOf the 1,809 citations, 7 studies with 2,854 patients (age 28 ± 4 years) were included. During 5.6 ± 3.4 years' follow-up, there were 82 deaths, 17 aborted sudden cardiac deaths, and 56 sustained ventricular tachycardia events. Overall, CAEs occurred in 5.1% (144 patients). As a continuous variable, LVEF was a predictor of CAE (HR 1.29, 95% CI, 1.09-1.53, P = 0.001) per 5% decrease in LVEF. Similarly, LVEF < 40% was also a predictor of CAE (HR 3.22, 95% CI, 2.16-4.80, P < 0.001).ConclusionsLV systolic dysfunction was an independent predictor of CAE, and we observed a 30% increase in the risk of CAE for every 5% decrease in LVEF, and a 3-fold increase in the risk of CAE in patients with LVEF <40% compared with other patients. These findings underscore the importance of incorporating LV systolic function in clinical risk stratification of patients with TOF and the need to explore new treatment options to address this problem.     

Incremental prognostic value of changes in B-type natriuretic peptide in heart failure

Purpose

B-type natriuretic peptide is one of the most sensitive and specific biohumoral markers of heart failure. We hypothesized that B-type natriuretic peptide changes during treatment of heart failure may provide independent information on disease progression and outcome in patients enrolled in the Val-HeFT trial.

Methods

Patients were divided into four groups according to concentrations of B-type natriuretic peptide at baseline versus 4 months (n = 3740) or 12 months (n = 3343), with respect to the baseline median (97 pg/mL): low→low (stable below median, 44%-46%), high→high (stable above median, 32%-37%), high→low (above to below median, 12%-14%), and low→high (below to above median, 6%-9%). Cox multivariate regression analysis was used to assess the risk of death and morbidity, with adjustment for baseline B-type natriuretic peptide concentrations.

Results

Patients who improved their B-type natriuretic peptide at 4 months (high→low) had a similar risk for mortality (hazard ratio = 1.191, 95% confidence interval [CI] 0.870-1.631, P =.2746) compared with the low→low patients. Conversely, patients who worsened in their B-type natriuretic peptide (low→high) had a risk for mortality (hazard ratio 2.578, CI, 1.861-3.571, P <.0001) higher than patients in the low→low group, and indistinguishable from the high→high group. Worsening of B-type natriuretic peptide (low→high) was associated with 0.03 cm/m² increase in left ventricular end-diastolic diameter, whereas it decreased by 0.10 cm/m² in high→low and low→low groups (P <.001).

Conclusions

Changes in B-type natriuretic peptide over time with respect to a threshold value of 97 pg/mL convey an independent and additional prognostic value compared with a single determination of B-type natriuretic peptide in a large population of patients with chronic symptomatic heart failure and might be helpful in the management of these patients.     

Antiplatelet agents in acute coronary syndromes

Plaque disruption, platelet activation, and intracoronary artery thrombus formation are the key events in the pathogenesis of acute coronary syndromes. Antiplatelet therapies significantly reduce the risk of ischemic complications both during the acute phase and in the long term in patients with acute coronary syndromes. Aspirin remains the cornerstone of antiplatelet therapy, but there is incremental benefit when clopidogrel or ticlopidine is added to aspirin. Dual antiplatelet therapy with the combination of clopidogrel and aspirin is becoming the new standard of care for the management of patients with non-ST-segment elevation acute coronary syndrome and undergoing percutaneous coronary intervention and is currently being further evaluated in ST-segment elevation acute coronary syndrome.     

Referrals in acute coronary events for CARdiac catheterization: The RACE CAR trial

BACKGROUND:

Women with acute coronary syndromes have lower rates of cardiac catheterization (CC) than men.

OBJECTIVE:

To determine whether sex/gender, age, risk level and patient preference influence physician decision making to refer patients for CC.

METHODS:

Twelve clinical scenarios controlling for sex/gender, age (55 or 75 years of age), Thrombolysis in Myocardial Infarction risk score (low, moderate or high) and patient preference for CC (agreeable or refused/no preference expressed) were designed. Scenarios were administered to specialists across Canada using a web-based computerized survey instrument. Questions were standardized using a five-point Likert scale ranging from 1 (very unlikely to benefit from CC) to 5 (very likely to benefit from CC). Outcomes were assessed using a two-tailed mixed linear regression model.

RESULTS:

Of 237 scenarios, physicians rated men as more likely to benefit from CC than women (mean [± SE] 4.44±0.07 versus 4.25±0.07, P=0.03), adjusted for age, risk and patient preference. Low-risk men were perceived to benefit more than low-risk women (4.20±0.13 versus 3.54±0.14, P<0.01), and low-risk younger patients were perceived to benefit more than low-risk older patients (4.52±0.17 versus 3.22±0.16, P<0.01). Regardless of risk, patients who agreed to CC were perceived as more likely to benefit from CC than patients who were disagreeable or made no comment at all (5.0±0.23, 3.67±0.21, 2.95±0.14, respectively, P<0.01).

CONCLUSION:

Canadian specialists’ decisions to refer patients for CC appear to be influenced by sex/gender, age and patient preference in clinical scenarios in which cardiac risk is held constant. Future investigation of possible age and sex/gender biases as proxies for risk is warranted.     

An In Vitro Stereomicroscopic Evaluation of Bioactivity between Neo MTA Plus,Pro Root MTA,BIODENTINE & Glass Ionomer Cement Using Dye Penetration Method

The ideal root end filling material should form a tight seal in the root canal by adhering to the cavity walls. Several materials have been used for root end filling. The present study aims to find out and compare the bioactivity of Neo MTA Plus, Pro Root MTA White, BIODENTINE & glass ionomer cement as root end filling materials using 1% methylene blue as tracer. Materials and methods: 80 extracted human permanent maxillary anterior teeth were used in the study. They were divided into four groups. Specimens were sectioned transversely in the cervical area to separate the crown from the root. The root canal was obturated with gutta percha and zinc oxide eugenol sealers. Thereafter, each sample was resected apically by removing 3 mm of the apex and filled with different materials. Samples were kept in buffering solution at 37 °C until the recommended evaluation periods. The specimens were then suspended in 1% methylene blue for 24 h, prior to the analysis. The teeth were then sectioned, and dye penetration was examined, photographed, and evaluated under a stereomicroscope. Results: Vertical dye penetration showed significant differences across different groups. The minimum dye penetration was seen in Neo MTA plus followed by BIODENTINE, Pro Root MTA and maximum in GIC. There was no significant difference in dye penetration between Neo MTA plus and BIODENTINE both at fifteen days and one-month intervals. Conclusion: The present study suggests Neo MTA plus and BIODENTINE should be the preferred material for root end filling.     

Periodontal disease and type 1 diabetes mellitus: Associations with glycemic control and complications: An Indian perspective

AimTo evaluate the frequency of periodontal disease in a group of patients with type 1 diabetes mellitus and its relationship with diabetic metabolic control, duration and complications.Materials and methodsA comparison was made of periodontal parameters (plaque index, bleeding index, pocket depth and attachment loss) in a group of diabetic patients versus a group of non-diabetics (n = 20). Statistical analysis was performed to evaluate the relationship between periodontal parameters and degree of metabolic control, the duration of the disease and the appearance of complications.ResultsDiabetics had greater bleeding index (p < 0.001), probing pocket depth (p < 0.001) and clinical attachment level (p = 0.001). Patients diagnosed for diabetes for shorter duration of time (4–7 years) showed bleeding index-disease severity correlation to be 1.760 ± 0.434.ConclusionPatients with type 1 diabetes have increased periodontal disease susceptibility. Periodontal inflammation is greatly increased in subjects with longer disease course, poor metabolic control and diabetic complications.     

Statistical models to predict the need for postoperative intensive care and hospitalization in pediatric surgical patients

OBJECTIVE: To develop statistical models for predicting postoperative hospital and ICU stay in pediatric surgical patients based on preoperative clinical characteristics and operative factors related to the degree of surgical stress. We hypothesized that preoperative and operative factors will predict the need for ICU admission and may be used to forecast the length of ICU stay or postoperative hospital stay. DESIGN: Prospective data collection from 1,763 patients. SETTING: Tertiary care children's hospital. PATIENTS AND PARTICIPANTS: All pediatric surgical patients, including those undergoing day surgery. Patients undergoing dental or ophthalmologic surgical procedures were excluded. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: A logistic regression model predicting ICU admission was developed from all patients. Poissonregression models were developed from 1,161 randomly selected patients and validated from the remaining 602 patients. The logistic regression model for ICU admission was highlypredictive (area under the receiver operating characteristics (ROC) curve = 0.981). In the data set used for development of Poisson regression models, significant correlations occurred between the observed and predicted ICU stay (Pearson r = 0.468, p < 0.0001, n = 131) and between the observed and predicted hospital stay for patients undergoing general (r = 0.695, p < 0.0001), orthopedic (r = 0.717, p < 0.0001), cardiothoracic (r = 0.746, p < 0.0001), urologic (r = 0.458, p < 0.0001), otorhinolaryngologic (r = 0.962, p < 0.0001), neurosurgical (r = 0.7084, p < 0.0001) and plastic surgical (r = 0.854, p < 0.0001) procedures. In the validation data set, correlations between predicted and observed hospital stay were significant for general (p < 0.0001), orthopedic (p < 0.0001), cardiothoracic (p = 0.0321) and urologic surgery (p = 0.0383). The Poisson models for length of ICU stay, otorhinolaryngology, neurosurgery or plastic surgery could not be validated because of small numbers of patients. CONCLUSIONS: Preoperative and operative factors may be used to develop statistical models predicting the need for ICU admission in pediatric surgical patients, and hospital stay following general surgical, orthopedic, cardiothoracic and urologic procedures. These statistical models need to be refined and validatedfurther, perhaps using data collection from multiple institutions.