Exposure reductions associated with introduction of solar lamps to kerosene lamp-using households in Busia County, Kenya

Solar lamps are a clean and potentially cost-effective alternative to polluting kerosene lamps used by millions of families in developing countries. By how much solar lamps actually reduce exposure to pollutants, however, has not been examined. Twenty households using mainly kerosene for lighting were enrolled through a secondary school in Busia County, Kenya. Personal PM_2.5 and CO concentrations were measured on a school pupil and an adult in each household, before and after provision of 3 solar lamps. PM_2.5 concentrations were measured in main living areas, pupils' bedrooms, and kitchens. Usage sensors measured use of kerosene and solar lighting devices. Ninety percent of baseline kerosene lamp use was displaced at 1-month follow-up, corresponding to average PM_2.5 reductions of 61% and 79% in main living areas and pupils' bedrooms, respectively. Average 48-h exposure to PM_2.5 fell from 210 to 104 μg/m³ (-50%) among adults, and from 132 to 35 μg/m³ (-73%) among pupils. Solar lamps displaced most kerosene lamp use in at least the short term. If sustained, this could mitigate health impacts of household air pollution in some contexts. Achieving safe levels of exposure for all family members would likely require also addressing use of solid-fuel stoves.

Frey's Syndrome

The history of Frey's syndrome is explored together with its physiopathological and anatomical basis. A study of 19 cases of parotidectomy in 15 patients is reviewed and the results of 17 tympanic neurectomies presented.

Automatic contour propagation using deformable image registration to determine delivered dose to spinal cord in head-and-neck cancer radiotherapy

To determine delivered dose to the spinal cord, a technique has been developed to propagate manual contours from kilovoltage computed-tomography (kVCT) scans for treatment planning to megavoltage computed-tomography (MVCT) guidance scans. The technique uses the Elastix software to perform intensity-based deformable image registration of each kVCT scan to the associated MVCT scans. The registration transform is then applied to contours of the spinal cord drawn manually on the kVCT scan, to obtain contour positions on the MVCT scans. Different registration strategies have been investigated, with performance evaluated by comparing the resulting auto-contours with manual contours, drawn by oncologists. The comparison metrics include the conformity index (CI), and the distance between centres (DBC). With optimised registration, auto-contours generally agree well with manual contours. Considering all 30 MVCT scans for each of three patients, the median CI is \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$0.759 \pm 0.003$ \end{document}0.759±0.003, and the median DBC is (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$0.87 \pm 0.01$ \end{document}0.87±0.01) mm. An intra-observer comparison for the same scans gives a median CI of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$0.820 \pm 0.002$ \end{document}0.820±0.002 and a DBC of (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$0.64 \pm 0.01$ \end{document}0.64±0.01) mm. Good levels of conformity are also obtained when auto-contours are compared with manual contours from one observer for a single MVCT scan for each of 30 patients, and when they are compared with manual contours from six observers for two MVCT scans for each of three patients. Using the auto-contours to estimate organ position at treatment time, a preliminary study of 33 patients who underwent radiotherapy for head-and-neck cancers indicates good agreement between planned and delivered dose to the spinal cord.

Delivered dose can be a better predictor of rectal toxicity than planned dose in prostate radiotherapy

Background and purpose

For the first time, delivered dose to the rectum has been calculated and accumulated throughout the course of prostate radiotherapy using megavoltage computed tomography (MVCT) image guidance scans. Dosimetric parameters were linked with toxicity to test the hypothesis that delivered dose is a stronger predictor of toxicity than planned dose.

Material and methods

Dose–surface maps (DSMs) of the rectal wall were automatically generated from daily MVCT scans for 109 patients within the VoxTox research programme. Accumulated-DSMs, representing total delivered dose, and planned-DSMs, from planning CT data, were parametrised using Equivalent Uniform Dose (EUD) and ‘DSM dose-width’, the lateral dimension of an ellipse fitted to a discrete isodose cluster. Associations with 6 toxicity endpoints were assessed using receiver operator characteristic curve analysis.

Results

For rectal bleeding, the area under the curve (AUC) was greater for accumulated dose than planned dose for DSM dose-widths up to 70 Gy. Accumulated 65 Gy DSM dose-width produced the strongest spatial correlation (AUC 0.664), while accumulated EUD generated the largest AUC overall (0.682). For proctitis, accumulated EUD was the only reportable predictor (AUC 0.673). Accumulated EUD was systematically lower than planned EUD.

Conclusions

Dosimetric parameters extracted from accumulated DSMs have demonstrated stronger correlations with rectal bleeding and proctitis, than planned DSMs.

Inhibitors of retrograde trafficking active against ricin and Shiga toxins also protect cells from several viruses, Leishmania and Chlamydiales

Medical countermeasures to treat biothreat agent infections require broad-spectrum therapeutics that do not induce agent resistance. A cell-based high-throughput screen (HTS) against ricin toxin combined with hit optimization allowed selection of a family of compounds that meet these requirements. The hit compound Retro-2 and its derivatives have been demonstrated to be safe in vivo in mice even at high doses. Moreover, Retro-2 is an inhibitor of retrograde transport that affects syntaxin-5-dependent toxins and pathogens. As a consequence, it has a broad-spectrum activity that has been demonstrated both in vitro and in vivo against ricin, Shiga toxin-producing O104:H4 entero-hemorrhagic E. coli and Leishmania sp. and in vitro against Ebola, Marburg and poxviruses and Chlamydiales. An effect is anticipated on other toxins or pathogens that use retrograde trafficking and syntaxin-5. Since Retro-2 targets cell components of the host and not directly the pathogen, no selection of resistant pathogens is expected. These lead compounds need now to be developed as drugs for human use.

Cortical Bone Porosity: What Is It, Why Is It Important, and How Can We Detect It?

There is growing recognition of the role of micro-architecture in osteoporotic bone loss and fragility. This trend has been driven by advances in imaging technology, which have enabled a transition from measures of mass to micro-architecture. Imaging trabecular bone has been a key research focus, but advances in resolution have also enabled the detection of cortical bone micro-architecture, particularly the network of vascular canals, commonly referred to as 'cortical porosity.' This review aims to provide an overview of what this level of porosity is, why it is important, and how it can be characterized by imaging. Moving beyond a 'trabeculocentric' view of bone loss holds the potential to improve diagnosis and monitoring of interventions. Furthermore, cortical porosity is intimately linked to the remodeling process, which underpins bone loss, and thus a larger potential exists to improve our fundamental understanding of bone health through imaging of both humans and animal models.

Risky driving among UK regular armed forces personnel: changes over time

OBJECTIVES

To compare the prevalence of self-reported risky driving in a sample of UK military personnel at 2 different time points (2004 and 2009), and to identify the incidence of new onset risky driving and possible determinants of becoming a new risky driver.

METHODS

Data were used from 2 phases of a military cohort study investigating the health and well-being of UK military personnel between 2004 and 2009. Participants were included if they were undertaking regular (rather than reserve) engagements, had completed both surveys and reported being a driver at both surveys. Univariable and multivariable logistic regression analyses were performed to examine the relationship between risky driving status and sociodemographic and military characteristics. Data analysis was conducted in 2011.

RESULTS

The prevalence of risky driving reduced from 18% to 14%, over an average of 3.3 years. The incidence of new onset risky driving was 7%. Predictors for becoming a new risky driver were: younger age, not being in a relationship at phase 2 and harmful alcohol use. Those deployed after 2007 were less likely to become risky drivers following deployment, compared with those deployed before 2007 (adjusted OR 0.62 (95% CI 0.40 to 0.95)).

CONCLUSIONS

The prevalence of becoming a risky driver appears to have reduced over time. This paper suggests a number of explanations for this reduction, including changes in the way that the UK military have dealt with road safety with the introduction of the road safety campaign (in 2007).

Effect of cryopreservation on the sperm DNA fragmentation dynamics of the bottlenose dolphin (Tursiops truncatus)

Sperm DNA fragmentation is one of the major causes of infertility; the sperm chromatin dispersion test (SCDt) evaluates this parameter and offers the advantage of species-specific validated protocol and ease of use under field conditions. The main purpose of this study was to evaluate sperm DNA fragmentation dynamics in both fresh and post-thaw bottlenose dolphin sperm using the SCDt following different cryopreservation protocols to gain new information about the post-thaw differential sperm DNA longevity in this species. Fresh and cryopreserved semen samples from five bottlenose dolphins were examined for sperm DNA fragmentation dynamics using the SCDt (Halomax(®)). Sperm DNA fragmentation was assessed immediately at collection and following cryopreservation (T0) and then after 0.5, 1, 4, 8, 24, 48 and 72 h incubation at 37°C. Serially collected ejaculates from four dolphins were frozen using different cryopreservation protocols in a TES-TRIS-fructose buffer (TTF), an egg-yolk-free vegetable lipid LP1 buffer (LP1) and human sperm preservation medium (HSPM). Fresh ejaculated spermatozoa initially showed low levels of DNA fragmentation for up to 48 h. Lower Sperm DNA fragmentation (SDF) was found in the second fresh ejaculate compared to the first when more than one sample was collected on the same day (p < 0.05); this difference was not apparent in any other seminal characteristic. While there was no difference observed in SDF between fresh and frozen-thawed sperm using the different cryopreservation protocols immediately after thawing (T0), frozen-thawed spermatozoa incubated at 37°C showed an increase in the rate of SDF after 24 h. Sperm frozen in the LP1(℗) buffer had higher levels (p < 0.05) of DNA fragmentation after 24- and 48-h incubation than those frozen in TTF or HSPM. No correlation was found between any seminal characteristic and DNA fragmentation in either fresh and/or frozen-thawed samples.

Random variation in rectal position during radiotherapy for prostate cancer is two to three times greater than that predicted from prostate motion

Objective:

Radiotherapy for prostate cancer does not explicitly take into account daily variation in the position of the rectum. It is important to accurately assess accumulated dose (D_A) to the rectum in order to understand the relationship between dose and toxicity. The primary objective of this work was to quantify systematic (Σ) and random (σ) variation in the position of the rectum during a course of prostate radiotherapy.

Methods:

The rectum was manually outlined on the kilo-voltage planning scan and 37 daily mega-voltage image guidance scans for 10 participants recruited to the VoxTox study. The femoral heads were used to produce a fixed point to which all rectal contours were referenced.

Results:

Σ [standard deviation (SD) of means] between planning and treatment was 4.2 mm in the anteroposterior (AP) direction and 1.3 mm left–right (LR). σ (root mean square of SDs) was 5.2 mm AP and 2.7 mm LR. Superior–inferior variation was less than one slice above and below the planning position.

Conclusion:

Our results for Σ are in line with published data for prostate motion. σ, however, was approximately twice as great as that seen for prostate motion. This suggests that D_A may differ from planned dose in some patients treated with radiotherapy for prostate cancer.

Advances in knowledge:

This work is the first to use daily imaging to quantify Σ and σ of the rectum in prostate cancer. σ was found to be greater than published data, providing strong rationale for further investigation of individual D_A.

Orally delivered water soluble Coenzyme Q10 (Ubisol-Q10) blocks on-going neurodegeneration in rats exposed to paraquat: potential for therapeutic application in Parkinson's disease

BACKGROUND

Paraquat, still used as an herbicide in some parts of the world, is now regarded as a dangerous environmental neurotoxin and is linked to the development Parkinson's disease (PD). Paraquat interacts with cellular redox systems and causes mitochondrial dysfunction and the formation of reactive oxygen species, which in turn, plays a crucial role in the pathophysiology of PD. Various antioxidant therapies have been explored with the expectations that they deliver health benefits to the PD patients, however, no such therapies were effective. Here we have tested the neuroprotective efficacy of a novel water-soluble CoQ10 (Ubisol-Q10), in a rat model of paraquat-induced neurodegeneration in order to evaluate its potential application in the management of PD.

RESULTS

We have developed a rat model of progressive nigrostriatal degeneration by giving rats five intraperitoneal injections of paraquat (10 mg/kg/injection), once every five days. Neuronal death occurred over a period of 8 weeks with close to 50% reduction in the number of tyrosine hydroxylase-positive cells. Ubisol-Q10, at 6 mg CoQ10/kg body weight/day, was delivered as a supplement in drinking water. The intervention begun after the completion of paraquat injections when the neurodegenerative process had already began and about 20% of TH-positive neurons were lost. Ubisol-Q10 treatment halted the progression of neurodegeneration and remaining neurons were protected. The outcomes were evaluated based on the number of surviving tyrosine hydroxylase-positive neurons in the substantia nigra region and improved motor skills in response to the Ubisol-Q10 intervention. To maintain this neuroprotection, however, continuous Ubisol- Q10 supplementation was required, if withdrawn, the neuronal death pathway resumed, suggesting that the presence of CoQ10 was essential for blocking the pathway.

CONCLUSION

The CoQ10, given orally as Ubisol-Q10 in drinking solution, was effective in blocking the progression of neurodegeneration when administered therapeutically (post-toxin injection), at a much lower concentration than other previously tested oil soluble formulations and well within the acceptable daily intake of 12 mg/kg/day. Such unprecedented neuroprotection has never been reported before. These results are very encouraging and suggest that Ubisol-Q10 should be further tested and developed as a therapy for halting the progression of PD.