Microsomal superoxide anion production and NADPH-oxidation in a series of 22 aziridinylbenzoquinones

Several 2,5-bis(1-aziridinyl)-1,4-benzoquinones (BABQs) can be activated to alkylating species by reduction of the quinone moiety. On the other hand, cytotoxicity of these compounds can be induced by redox cycling. A series of BABQs and their methylated analogues (BMABQs) with different substituents at the 3- and 6-position was synthesized in order to investigate the influence of the substituents on the reduction of the quinone moiety and on the generation of superoxide anion radicals with rat liver microsomes. Superoxide anion production (SAP) ranged from 3.7±0.1 to 742±74 nmoles/min/mg protein with quinone concentrations of 10 nmoles/ml. NADPH-oxidation was measured under the same conditions and it correlated well (r = 0.88, P < 0.001) with SAP. It ranged from 1.4±0.2 to 494±60 nmoles/min/mg protein. SAP for 22 B(M)ABQs showed a good correlation with the summated electronic substituent constant θpara,total (r = 0.86, P < 0.001). It can be concluded that superoxide anion production by 22 B(M)ABQs in rat liver microsomes can be predicted from structural features of the compounds

Stages of development and injury: an epidemiological survey of young children presenting to an emergency department

&lt;p&gt;&lt;b&gt;Background:&lt;/b&gt; The aim of our study was to use a local (Glasgow, west of Scotland) version of a Canadian injury surveillance programme (CHIRPP) to investigate the relationship between the developmental stage of young (pre-school) children, using age as a proxy, and the occurrence (incidence, nature, mechanism and location) of injuries presenting to a Scottish hospital emergency department, in an attempt to replicate the findings of a recent study in Kingston, Canada.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods:&lt;/b&gt; We used the Glasgow CHIRPP data to perform two types of analyses. First, we calculated injury rates for that part of the hospital catchment area for which reasonably accurate population denominators were available. Second, we examined detailed injury patterns, in terms of the circumstances, mechanisms, location and types of injury. We compared our findings with those of the Kingston researchers.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Results:&lt;/b&gt; A total of 17,793 injury records for children aged up to 7 years were identified over the period 1997–99. For 1997–2001, 6,188 were used to calculate rates in the west of the city only. Average annual age specific rates per 1000 children were highest in both males and females aged 12–35 months. Apart from the higher rates in Glasgow, the pattern of injuries, in terms of breakdown factors, mechanism, location, context, and nature of injury, were similar in Glasgow and Kingston.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusion:&lt;/b&gt; We replicated in Glasgow, UK, the findings of a Canadian study demonstrating a correlation between the pattern of childhood injuries and developmental stage. Future research should take account of the need to enhance statistical power and explore the interaction between age and potential confounding variables such as socio-economic deprivation. Our findings highlight the importance of designing injury prevention interventions that are appropriate for specific stages of development in children.&lt;/p&gt

Seed systems smallholder farmers use

Seed can be an important entry point for promoting productivity, nutrition and resilience among smallholder farmers. While investments have primarily focused on strengthening the formal sector, this article documents the degree to which the informal sector remains the core for seed acquisition, especially in Africa. Conclusions drawn from a uniquely comprehensive data set, 9660 observations across six countries and covering 40 crops, show that farmers access 90.2 % of their seed from informal systems with 50.9 % of that deriving from local markets. Further, 55 % of seed is paid for by cash, indicating that smallholders are already making important investments in this arena. Targeted interventions are proposed for rendering formal and informal seed sector more smallholder-responsive and for scaling up positive impacts

Studying Cat (Felis catus) Diabetes: Beware of the Acromegalic Imposter

Naturally occurring diabetes mellitus (DM) is common in domestic cats (Felis catus). It has been proposed as a model for human Type 2 DM given many shared features. Small case studies demonstrate feline DM also occurs as a result of insulin resistance due to a somatotrophinoma. The current study estimates the prevalence of hypersomatotropism or acromegaly in the largest cohort of diabetic cats to date, evaluates clinical presentation and ease of recognition. Diabetic cats were screened for hypersomatotropism using serum total insulin-like growth factor-1 (IGF-1; radioimmunoassay), followed by further evaluation of a subset of cases with suggestive IGF-1 (>1000 ng/ml) through pituitary imaging and/ or histopathology. Clinicians indicated pre-test suspicion for hypersomatotropism. In total 1221 diabetic cats were screened; 319 (26.1%) demonstrated a serum IGF-1>1000 ng/ml (95% confidence interval: 23.6-28.6%). Of these cats a subset of 63 (20%) underwent pituitary imaging and 56/63 (89%) had a pituitary tumour on computed tomography; an additional three on magnetic resonance imaging and one on necropsy. These data suggest a positive predictive value of serum IGF-1 for hypersomatotropism of 95% (95% confidence interval: 90-100%), thus suggesting the overall hypersomatotropism prevalence among UK diabetic cats to be 24.8% (95% confidence interval: 21.2-28.6%). Only 24% of clinicians indicated a strong pre-test suspicion; most hypersomatotropism cats did not display typical phenotypical acromegaly signs. The current data suggest hypersomatotropism screening should be considered when studying diabetic cats and opportunities exist for comparative acromegaly research, especially in light of the many detected communalities with the human disease

Sex differences in mathematics and reading achievement are inversely related: within- and across-nation assessment of 10 years of PISA data

We analyzed one decade of data collected by the Programme for International Student Assessment (PISA), including the mathematics and reading performance of nearly 1.5 million 15 year olds in 75 countries. Across nations, boys scored higher than girls in mathematics, but lower than girls in reading. The sex difference in reading was three times as large as in mathematics. There was considerable variation in the extent of the sex differences between nations. There are countries without a sex difference in mathematics performance, and in some countries girls scored higher than boys. Boys scored lower in reading in all nations in all four PISA assessments (2000, 2003, 2006, 2009). Contrary to several previous studies, we found no evidence that the sex differences were related to nations’ gender equality indicators. Further, paradoxically, sex differences in mathematics were consistently and strongly inversely correlated with sex differences in reading: Countries with a smaller sex difference in mathematics had a larger sex difference in reading and vice versa. We demonstrate that this was not merely a between-nation, but also a within-nation effect. This effect is related to relative changes in these sex differences across the performance continuum: We did not find a sex difference in mathematics among the lowest performing students, but this is where the sex difference in reading was largest. In contrast, the sex difference in mathematics was largest among the higher performing students, and this is where the sex difference in reading was smallest. The implication is that if policy makers decide that changes in these sex differences are desired, different approaches will be needed to achieve this for reading and mathematics. Interventions that focus on high-achieving girls in mathematics and on low achieving boys in reading are likely to yield the strongest educational benefits

Epidemiologic Evidence on the Health Effects of Perfluorooctanoic Acid (PFOA)

UNLABELLED: OBJECTIVE AND SOURCES: We reviewed the epidemiologic literature for PFOA. DATA SYNTHESIS: Perfluorooctanoic acid (PFOA) does not occur naturally but is present in the serum of most residents of industrialized countries (U.S. median, 4 ng/mL). Drinking water is the primary route of exposure in some populations, but exposure sources are not well understood. PFOA has been used to manufacture such products as Gore-Tex and Teflon. PFOA does not break down in the environment; the human half-life is estimated at about 3 years. PFOA is not metabolized in the body; it is not lipophilic. PFOA is not directly genotoxic; animal data indicate that it can cause several types of tumors and neonatal death and may have toxic effects on the immune, liver, and endocrine systems. Data on the human health effects of PFOA are sparse. There is relatively consistent evidence of modest positive associations with cholesterol and uric acid, although the magnitude of the cholesterol effect is inconsistent across different exposure levels. There is some but much less consistent evidence of a modest positive correlation with liver enzymes. Most findings come from cross-sectional studies, limiting conclusions. Two occupational cohort studies do not provide consistent evidence for chronic disease; both are limited by sample size and reliance on mortality data. Reproductive data have increased recently but are inconsistent, and any observed adverse effects are modest. CONCLUSIONS: Epidemiologic evidence remains limited, and to date data are insufficient to draw firm conclusions regarding the role of PFOA for any of the diseases of concern

Ultrasonic Needle Tracking with Dynamic Electronic Focusing

Accurate identification of the needle tip is a key challenge with ultrasound-guided percutaneous interventions in regional anaesthesia, foetal surgery and cardiovascular medicine. In this study, we developed an ultrasonic needle tracking system in which the measured needle tip location was used to set the electronic focus of the external ultrasound imaging probe. In this system, needle tip tracking was enabled with a fibre-optic ultrasound sensor that was integrated into a needle stylet, and the A-lines recorded by the sensor were processed to generate tracking images of the needle tip. The needle tip position was estimated from the tracking images. The dependency of the tracking image on the electronic focal depth of the external ultrasound imaging probe was studied in a water bath and with needle insertions into a clinical training phantom. The variability in the estimated tracked position of the needle tip, with the needle tip at fixed depths in the imaging plane across a depth range from 0.5 to 7.5 cm, was studied. When the electronic focus was fixed, the variability of tracked position was found to increase with distance from that focus. The variability with the fixed focus was found to depend on the the relative distance between the needle tip and focal depth. It was found that with dynamic focusing, the maximum variability of tracked position was below 0.31 mm, as compared with 3.97 mm for a fixed focus