Risky and aggressive driving in young adults: Personality matters

Young, novice drivers constitute a disproportionate percentage of fatalities and injuries in road traffic accidents around the world. This study, attempts to identify motivational factors behind risky driving behavior, and examines the role of personality, especially sensation seeking, impulsivity and sensitivity to punishment/reward in predicting negative driving outcomes (accident involvement and traffic offences) among young drivers. Gender and driver's age are additional factors examined in relation to driving outcomes and personality. Adopting the contextual mediated model of traffic accident involvement (Sümer, 2003), the study is based on the theory that personality, age and gender represent distal factors that predict accident involvement indirectly through their relationship with stable tendencies towards aberrant driving behavior. Results from correlations and Structural Equation Modeling using AMOS 6 indicated that direct personality effects on driving outcomes were few, whereas personality had significant correlations with aberrant driving behavior, showing that personality is a distal but important predictor of negative driving outcomes. These high risk traits appear to be at a peak among young male drivers. Thus, personality is important in understanding aggressive and risky driving by young adults and needs to be taken into consideration in designing targeted accident prevention policies.     

Peripheral blood progenitor cell mobilization using stem cell factor in combination with filgrastim in breast cancer patients

The safety and optimal dose and schedule of stem cell factor (SCF) administered in combination with filgrastim for the mobilization of peripheral blood progenitor cells (PBPCs) was determined in 215 patients with high-risk breast cancer. Patients received either filgrastim alone (10 microg/kg/d for 7 days) or the combination of 10 microg/kg/d filgrastim and 5 to 30 microg/kg/d SCF for either 7, 10, or 13 days. SCF patients were premedicated with antiallergy prophylaxis. Leukapheresis was performed on the final 3 days of cytokine therapy and, after high-dose chemotherapy and infusion of PBPCs, patients received 10 microg/kg/d filgrastim until absolute neutrophil count recovery. The median number of CD34+ cells collected was greater for patients receiving the combination of filgrastim and SCF, at doses greater than 10 microg/kg/d, than for those receiving filgrastim alone (7.7 v 3.2 x 10(6)/kg, P < .05). There were significantly (P < .05) more CD34+ cells harvested for the 20 microg/kg/d SCF (median, 7.9 x 10(6)/kg) and 25 microg/kg/d SCF (median, 13.6 x 10(6)/kg) 7-day combination groups than for the filgrastim alone patients (median, 3.2 x 10(6)/kg). The duration of administration of SCF and filgrastim (7, 10, or 13 days) did not significantly affect CD34+ cell yield. Treatment groups mobilized with filgrastim alone or with the cytokine combination had similar hematopoietic engraftment and overall survival after PBPC infusion. In conclusion, the results of this study indicate that SCF therapy enhances CD34+ cell yield and is associated with manageable levels of toxicity when combined with filgrastim for PBPC mobilization. The combination of 20 microg/kg/d SCF and 10 microg/kg/d filgrastim with daily apheresis beginning on day 5 was selected as the optimal dose and schedule for the mobilization of PBPCs.     

Anterior segment sparing to reduce charged particle radiotherapy complications in uveal melanoma

PURPOSE: The purpose of this investigation is to delineate the risk factors in the development of neovascular glaucoma (NVG) after helium-ion irradiation of uveal melanoma patients and to propose treatment technique that may reduce this risk. METHODS AND MATERIALS: 347 uveal melanoma patients were treated with helium-ions using a single-port treatment technique. Using univariate and multivariate statistics, the NVG complication rate was analyzed according to the percent of anterior chamber in the radiation field, tumor size, tumor location, sex, age, dose, and other risk factors. Several University of California San Francisco-Lawrence Berkeley National Laboratory (LBNL) patients in each size category (medium, large, and extralarge) were retrospectively replanned using two ports instead of a single port. By using appropriate polar and azimuthal gaze angles or by treating patients with two ports, the maximum dose to the anterior segment of the eye can often be reduced. Although a larger volume of anterior chamber may receive a lower dose by using two ports than a single port treatment. We hypothesize that this could reduce the level of complications that result from the irradiation of the anterior chamber of the eye. Dose-volume histograms were calculated for the lens, and compared for the single and two-port techniques. RESULTS: NVG developed in 121 (35%) patients. The risk of NVG peaked between 1 and 2.5 years posttreatment. By univariate and multivariate analysis, the percent of lens in the field was strongly correlated with the development of NVG. Other contributing factors were tumor height, history of diabetes, and vitreous hemorrhage. Dose-volume histogram analysis of single-port vs. two-port techniques demonstrate that for some patients in the medium and large category tumor groups, a significant decrease in dose to the structures in the anterior segment of the eye could have been achieved with the use of two ports. CONCLUSION: The development of NVG after helium-ion irradiation is correlated to the amount of lens, anterior chamber in the treatment field, tumor height, proximity to the fovea, history of diabetes, and the development of vitreous hemorrhage. Although the influence of the higher LET deposition of helium-ions is unclear, this study suggests that by reducing the dose to the anterior segment of the eye may reduce the NVG complications. Based on this retrospective analysis of LBNL patients, we have implemented techniques to reduce the amount of the anterior segment receiving a high dose in our new series of patients treated with protons using the cyclotron at the UC Davis Crocker Nuclear Laboratory (CNL).     

Effects of prior therapy on the in vitro proliferative potential of stem cell factor plus filgrastim-mobilized CD34-positive progenitor cells

The quantity of hematopoietic progenitors in an apheresis collection is defined by the number of CD34(+) cells or granulocyte macrophage colony-forming units present. These parameters are believed to give roughly equivalent information on graft quality. We here report that the in vitro proliferative potential of r-metHuSCF (stem cell factor) plus filgrastim (granulocyte colony-stimulating factor; r-metHuG-CSF) mobilized peripheral blood (PB) CD34(+) cells obtained from previously heavily treated non-Hodgkin's lymphoma patients inversely correlates with extent of prior therapy. CD34(+) cells were enriched using the CellPro Ceprate system and placed in liquid culture for 4 weeks in the presence of either r-metHuSCF, IL-3, IL-6, filgrastim (S36G), or S36G plus erythropoietin (S36GE) with a weekly exchange of media and cytokines with reestablishment of culture at the starting cell concentration (Delta assay) and enumeration of progenitors. Starting with 4 x 10(4) CD34(+) cells from apheresis samples from patients who had received <10 cycles of prior chemotherapy, progenitors were detectable in culture at 4 weeks 81% of the time as compared to 14% with CD34(+) cells from patients who had received >10 cycles and 5% for >10 cycles plus radiotherapy. The total number of progenitors generated over the duration of culture (area under the curve) was calculated using the trapezoidal rule as a novel measure of the proliferative potential of the enriched PB CD34(+) cell population. The median area under the curve of CD34(+) cells from patients receiving <10 cycles of prior chemotherapy was 7.4 and 5.7 (x10(5)) using S36G or S36GE, respectively, 1.8 and 1.9 if the patients received >10 cycles of prior chemotherapy, and 1.4 and 1.2 if the patients received >10 cycles of prior chemotherapy plus radiotherapy (P < 0.001). These data show that prior therapy impacts on the quality of PB CD34(+) cells as measured by their ability to generate committed progenitors over a number of weeks in liquid culture.     

Cyclohexyl nitrite encounter

A brown glass bottle containing yellow liquid was submitted for examination for the presence of common controlled substances. While no controlled substances were detected, the liquid was identified as impure cyclohexyl nitrite, a compound of the same chemical class as amyl and butyl nitrite, which are known for their abuse potential. A bottle labeled cyclohexyl nitrite, but not confirmed by analysis, is the only known previous case submitted to this lab. The case history, examination, and analytical results are presented.     

On the Efficient Generation of Prime-Order Elliptic Curves

We consider the generation of prime-order elliptic curves (ECs) over a prime field \mathbbF_p\mathbb{F}_{p} using the Complex Multiplication (CM) method. A crucial step of this method is to compute the roots of a special type of class field polynomials with the most commonly used being the Hilbert and Weber ones. These polynomials are uniquely determined by the CM discriminant D. In this paper, we consider a variant of the CM method for constructing elliptic curves (ECs) of prime order using Weber polynomials. In attempting to construct prime-order ECs using Weber polynomials, two difficulties arise (in addition to the necessary transformations of the roots of such polynomials to those of their Hilbert counterparts). The first one is that the requirement of prime order necessitates that D≡3mod8), which gives Weber polynomials with degree three times larger than the degree of their corresponding Hilbert polynomials (a fact that could affect efficiency). The second difficulty is that these Weber polynomials do not have roots in \mathbbF_p\mathbb{F}_{p} .