Comparative toxicity of azinphos-methyl to house mice, laboratory mice, deer mice, and gray-tailed voles

A laboratory toxicity study on house mice and laboratory mice (Mus musculus), gray-tailed voles (Microtus canicaudus), and deer mice (Peromyscus maniculatus) was conducted as part of a comprehensive laboratory and field study to field validate laboratory-based risk assessment of pesticides. The single dose oral LD50 for the organophosphorus insecticide azinphos-methyl (Guthion) was 10, 11, 32, and 48 mg/kg body weight in wild house mice, laboratory mice, gray-tailed voles, and deer mice, respectively. Ten-day dietary LC50s were 277 ppm for laboratory mice, 297 ppm for gray-tailed voles, and 1,180 ppm for deer mice. All treated animals lost more weight, consumed less food, and had depressed brain cholinesterase (ChE) activity compared to controls. Five-day LC50s were significantly higher than 10-day LC50s for laboratory mice and deer mice. For all three species, animals that died during dietary LC50 tests had mean ChE activity of 50-55% while survivors had 56-70% of controls. The conclusions were that: (1) Laboratory mice were not representative of deer mice or gray-tailed voles with respect to sensitivity to azinphos-methyl, but provided a conservative estimate for risk assessment; (2) 10-day dietary LC50 tests indicate substantially greater estimates of toxicity of azinphos-methyl to rodents than do 5-day tests; and (3) brain ChE depression of 45-50% was lethal in these species.     

Intensive postremission chemotherapy in adults with acute myeloid leukemia. Cancer and Leukemia Group B

BACKGROUND: About 65 percent of previously untreated adults with primary acute myeloid leukemia (AML) enter complete remission when treated with cytarabine and an anthracycline. However, such responses are rarely durable when conventional postremission therapy is administered. Uncontrolled trials have suggested that intensive postremission therapy may prolong these complete remissions. METHODS: We treated 1088 adults with newly diagnosed AML with three days of daunorubicin and seven days of cytarabine and randomly assigned patients who had a complete remission to receive four courses of cytarabine at one of three doses: 100 mg per square meter of body-surface area per day for five days by continuous infusion, 400 mg per square meter per day for five days by continuous infusion, or 3 g per square meter in a 3-hour infusion every 12 hours (twice daily) on days 1, 3, and 5. All patients then received four courses of monthly maintenance treatment. RESULTS: Of the 693 patients who had a complete remission, 596 were randomly assigned to receive postremission cytarabine. After a median follow-up of 52 months, the disease-free survival rates in the three treatment groups were significantly different (P = 0.003). Relative to the 100-mg group, the hazard ratios were 0.67 for the 3-g group (95 percent confidence interval, 0.53 to 0.86) and 0.75 for the 400-mg group (95 percent confidence interval, 0.60 to 0.94). The probability of remaining in continuous complete remission after four years for patients 60 years of age or younger was 24 percent in the 100-mg group, 29 percent in the 400-mg group, and 44 percent in the 3-g group (P = 0.002). In contrast, for patients older than 60, the probability of remaining disease-free after four years was 16 percent or less in each of the three postremission cytarabine groups. CONCLUSIONS: These data support the concept of a dose-response effect for cytarabine in patients with AML who are 60 years of age or younger. The results with the high-dose schedule in this age group are comparable to those reported in similar patients who have undergone allogeneic bone marrow transplantation during a first remission.     

Modeling considerations in seismic assessment of RC bridges using state-of-practice structural analysis software tools

The increasing awareness of the general society toward the seismic safety of structures has led to more restrictive performance requirements hence, many times, to the need of using new and more accurate methods of analysis of structures. Among these, nonlinear static procedures are becoming, evermore, the preferred choice of the majority of design codes, as an alternative to complete nonlinear time-history analysis for seismic design and assessment of structures. The many available software tools should therefore be evaluated and well understood, in order to be easily and soundly employed by the practitioners. The study presented herein intends to contribute to this need by providing further insight with respect to the use of commonly employed structural analysis software tools in nonlinear analysis of bridge structures. A comparison between different nonlinear modeling assumptions is presented, together with the comparison with real experimental results. Furthermore, alternative adaptive pushover procedures are proposed and applied to a case study bridge, based on a generic plastic hinge model. The adopted structural analysis program proved to be accurate, yielding reliable estimates, both in terms of local plastic hinge behavior and global structural behavior.     

Fatigue crack in large-scale tubular joints for offshore structures

Tubular members have been used for constructing offshore structures. Large-scale fatigue tests of welded tubular K-joints under the balanced in-plane bending brace were carried out to investigate the fatigue behavior of API 2W Gr.50 steel produced by POSCO. The experimental results were verified by numerical approaches and compared with the IIW, DnV RP-C203 and API RP 2A-WSD design curves. The test results based on the hot spot stress were in agreement with the design curves. The SCF factor for tubular K-jo...     

Fibroblasts Cultured on Nanowires Exhibit Low Motility,Impaired Cell Division,and DNA Damage

Nanowires are commonly used as tools for interfacing living cells, acting as biomolecule‐delivery vectors or electrodes. It is generally assumed that the small size of the nanowires ensures a minimal cellular perturbation, yet the effects of nanowires on cell migration and proliferation remain largely unknown. Fibroblast behaviour on vertical nanowire arrays is investigated, and it is shown that cell motility and proliferation rate are reduced on nanowires. Fibroblasts cultured on long nanowires exhibit failed cell division, DNA damage, increased ROS content and respiration. Using focused ion beam milling and scanning electron microscopy, highly curved but intact nuclear membranes are observed, showing no direct contact between the nanowires and the DNA. The nanowires possibly induce cellular stress and high respiration rates, which trigger the formation of ROS, which in turn results in DNA damage. These results are important guidelines to the design and interpretation of experiments involving nanowire‐based transfection and electrical characterization of living cells.     

Scanning the controls: genomics and nanotechnology

We outline some of the possible applications of nanotechnology to modern molecular biology and discuss several technologies that can be used to make nanoscale confining environments (channels or post arrays) for long polymers such as DNA. A particular emphasis is placed on making large arrays using non-electron beam lithography methods. We then discuss how focused ion beam (FIB) milling can be used to construct nearfield slits for examining molecules     

Shelf-life of Sterile Yellow-eyed Mullet (Aldrichetta forsteri) at 4°C

The relative effects of microbial and nonmicrobial spoilage on the shelf-life of yellow-eyed mullet were studied. Results of sensory and chemical analyses of sterile flesh stored at 4°C were compared with fillets which had either spoiled naturally while held at 4°C or frozen fillets held at ?18°C. Inosine was produced rapidly in both treatments at 4°C, followed in sterile flesh by a slower breakdown to hypoxan-thine. Hypoxanthine production from inosine was rapid in the presence of bacteria. Within 6 days sensory changes were observed in the frozen flesh and after 69 days, it was considered unacceptable. The development of off-odors and off-flavors in the absence of bacteria was not sufficiently slow to result in a significant extension in shelf-life for this species.     

Quantifying psychological victimization: scientific uncertainty, legal necessity

Quantifying psychological victimization presents a formidable conundrum for psychiatry and the law. On the one hand, the task is fundamentally uncertain, due to causal complexity that includes disparity between projected image and inner reality, context dependence, volition, and conflicting interests. On the other hand, the task is necessary for just determination in such areas of law as disability assessment, victim impact, compensation, and psychological crimes such as harassment. A multiaxial protocol is proposed to meet this problematic charge. The five dimensions of this protocol are (1) gross estimate of victimization, including severity of the stressor, the degree of resulting impairment, and variably, the degree of the victim's nonresponsibility; (2) reliability; (3) other conditions; (4) conflicts of interest; and (5) evaluator bias. Intuitive estimates are used widely here instead of operationalized criteria, to enhance flexibility and widen relevance. Evaluators are asked to determine and explain the weighting that should be given to different factors and to give a self-statement of their own biases.     

RasGRP, a Ras guanyl nucleotide- releasing protein with calcium- and diacylglycerol-binding motifs

RasGRP, a guanyl nucleotide-releasing protein for the small guanosine triphosphatase Ras, was characterized. Besides the catalytic domain, RasGRP has an atypical pair of "EF hands" that bind calcium and a diacylglycerol (DAG)-binding domain. RasGRP activated Ras and caused transformation in fibroblasts. A DAG analog caused sustained activation of Ras-Erk signaling and changes in cell morphology. Signaling was associated with partitioning of RasGRP protein into the membrane fraction. Sustained ligand-induced signaling and membrane partitioning were absent when the DAG-binding domain was deleted. RasGRP is expressed in the nervous system, where it may couple changes in DAG and possibly calcium concentrations to Ras activation.     

Dietary risk factors for pre-eclampsia among women attending Harare Maternity Hospital, Zimbabwe

OBJECTIVE: To identify specific foods that predispose Zimbabwean women to a higher or lower risk of pre-eclampsia and/or eclampsia. DESIGN: A case control study was implemented. Participants were asked by questionnaire to recall the specific amounts of meats, poultry, fruits, fish, vegetables and dairy products they had consumed in the month prior to giving birth. SETTING: Harare Maternity Hospital, Harare, Zimbabwe between June of 1995 and April of 1996. SUBJECTS: 180 women clinically diagnosed with pre-eclampsia (144) or eclampsia (36), and 194 normotensive women without these conditions. MAIN OUTCOME MEASURES: Pre-eclampsia/eclampsia. RESULTS: There were few associations between consumption of specific food items and the occurrence of pre-eclampsia/eclampsia. Meat and fruit were the only foods found to be significantly associated with pre-eclampsia. Women who consumed 12 or more servings of meat per month were more likely to have pre-eclampsia/eclampsia when compared to women eating 11 servings of meat or less per month. While intake of bananas and mangos was unrelated to risk, women who consumed other fruits (i.e. apples, oranges, grapes, peaches, apricots, paw paw, and plums), were 1.7 (95% CI = 1.0 to 3.1) times more likely to develop pre-eclampsia/eclampsia as women who ate none of these fruits. However, women who consumed relatively large quantities of these fruits were not at a particularly high risk. Increased consumption of kapenta was modestly associated with a decrease in disease risk, but this finding was well within the limits of chance and no association was present with intake of other types of fish. CONCLUSIONS: Our findings suggest that variation in consumption of specific foods do not have a strong effect on the incidence of pre-eclampsia in this population. However, further research involving the use of a more comprehensive dietary measure, biochemical measurements of nutrients, pre-pregnancy assessment and ascertainment of dietary intake prior to the development of pre-eclampsia are needed.