History of ocular straylight measurement: A review

The earliest studies on ‘disability glare’ date from the early 20^th century. The condition was defined as the negative effect on visual function of a bright light located at some distance in the visual field. It was found that for larger angles (>1degree) the functional effect corresponded precisely to the effect of a light with a luminosity equal to that of the light that is perceived spreading around such a bright source. This perceived spreading of light was called straylight and by international standard disability glare was defined as identical to straylight. The phenomenon was recognized in the ophthalmological community as an important aspect of the quality of vision and attempts were made to design instruments to measure it. This must not be confused with instruments that assess light spreading over small distances (<1 degree), as originating from (higher order) aberrations and defocus. In recent years a new instrument has gained acceptance (C-Quant) for objective and controllable assessment of straylight in the clinical setting. This overview provides a sketch of the historical development of straylight measurement, as well as the results of studies on the origins of straylight (or disability glare) in the normal eye, and on findings on cataract (surgery) and corneal conditions.     

Liver Kupffer cells rapidly remove red blood cell-derived vesicles from the circulation by scavenger receptors

Previous studies have shown that during the lifespan of red blood cells (RBCs) 20% of hemoglobin is lost by shedding of hemoglobin-containing vesicles. However, the fate of these vesicles is unknown. To study this fate we used a rat model, after having established that rat RBCs lose hemoglobin in the same way as human RBCs, and that RBC-derived vesicles are preferentially labeled by Na2(51) CrO4. Such labeled vesicles were injected into recipient rats. Within 5 minutes, 80% of the radioactivity was cleared from the circulation with a concomitant uptake by the liver of 55% of the injected dose. After 30 minutes, Kupffer cells contained considerable amounts of hemoglobin and were shown to be responsible for 92% of the liver uptake. Vesicle clearance from the blood as well as liver uptake were significantly inhibited by preinjection of the scavenger-receptor ligands polyinosinic acid and phosphatidylserine. We conclude that in rats Kupffer cells rapidly remove RBC-derived vesicles from the circulation, mainly by scavenger receptors. The same mechanism is likely to be responsible for the elimination of human RBC vesicles, thereby constituting an important pathway for the breakdown of RBCs in humans.     

Age, gender and litter-related variation in T-lymphocyte cytokine production in young pigs

The capacity of farm animals to produce cytokines could be an important determinant of robustness and health. From research in rodents and humans it appears that the production and the balance of T helper 1 (Th1) and T helper 2 (Th2)-type cytokines influences susceptibility to autoimmune and infectious diseases. It is known that pigs show a large variation in many immune response parameters. So far the extent of individual variation in the production of Th1- and Th2-type cytokines in commercial outbred pigs has not been reported. In the current experiment we determined mRNA expression, as well as protein production of cytokines in 32 pigs from eight litters. From each litter two male and two female pigs were tested at 2, 5 and 8 weeks of age. Two Th1-type cytokines, interleukin (IL)-2 and interferon (IFN)-gamma, and two Th2-type cytokines, IL-4 and IL-10, were measured after phytohaemagglutinin (PHA)-stimulation of blood mononuclear cells. Cytokine production and the Th1/Th2-ratio were highly variable. The variation in cytokine protein production was moderately consistent across ages, i.e. pigs that produced high levels of cytokine at 2 weeks of age tended to do so as well at 5 and 8 weeks of age. Cytokine production tended to increase with age, and gilts and boars differed in their IL-2/IL-4 ratio. Unexpectedly, age, gender and litter effects often differed for mRNA and protein production data. We hypothesize that cytokine production is a consistent trait in pigs, especially at the protein production level. Future investigations in more animals and across a wider age range are necessary.     

Testosterone administration impairs cognitive empathy in women depending on second-to-fourth digit ratio

During social interactions we automatically infer motives, intentions, and feelings from bodily cues of others, especially from the eye region of their faces. This cognitive empathic ability is one of the most important components of social intelligence, and is essential for effective social interaction. Females on average outperform males in this cognitive empathy, and the male sex hormone testosterone is thought to be involved. Testosterone may not only down-regulate social intelligence organizationally, by affecting fetal brain development, but also activationally, by its current effects on the brain. Here, we show that administration of testosterone in 16 young women led to a significant impairment in their cognitive empathy, and that this effect is powerfully predicted by a proxy of fetal testosterone: the right-hand second digit-to-fourth digit ratio. Our data thus not only demonstrate down-regulatory effects of current testosterone on cognitive empathy, but also suggest these are preprogrammed by the very same hormone prenatally. These findings have importance for our understanding of the psychobiology of human social intelligence.     

Intragenic recombination generated two distinct Cf genes that mediate AVR9 recognition in the natural population of Lycopersicon pimpinellifolium

Resistance gene Cf-9 of cultivated tomato (Lycopersicon esculentum) confers recognition of the AVR9 elicitor protein of the fungal pathogen Cladosporium fulvum. The Cf-9 locus, containing Cf-9 and four homologs (Hcr9s), originates from Lycopersicon pimpinellifolium (Lp). We examined naturally occurring polymorphism in Hcr9s that confer AVR9 recognition in the Lp population. AVR9 recognition occurs frequently throughout this population. In addition to Cf-9, we discovered a second gene in Lp, designated 9DC, which also confers AVR9 recognition. Compared with Cf-9, 9DC is more polymorphic, occurs more frequently, and is more widely spread throughout the Lp population, suggesting that 9DC is older than Cf-9. The sequences of Cf-9 and 9DC suggest that Cf-9 evolved from 9DC by intragenic recombination between 9DC and another Hcr9. The fact that the 9DC and Cf-9 proteins differ in 61 aa residues, and both mediate recognition of AVR9, shows that in nature Hcr9 proteins with the same recognitional specificity can vary significantly.     

Mortality and malnutrition among populations living in South Darfur, Sudan: results of 3 surveys, September 2004

Context  Mass violence against civilians in the west of Sudan has resulted in the displacement of more than 1.5 million people (25% of the population of the Darfur region). Most of these people are camped in 142 settlements. There has been increasing international concern about the health status of the displaced population. Objective  To perform rapid epidemiological assessments of mortality and nutritional status at 3 sites in South Darfur for relief efforts. Design, Setting, and Participants  In August and September 2004, mortality surveys were conducted among 137 000 internally displaced persons (IDPs) in 3 sites in South Darfur (Kass [n = 900 households], Kalma [n = 893 households], and Muhajiria [n = 900 households]). A nutritional survey was performed concomitantly among children aged 6 to 59 months using weight for height as an index of acute malnutrition (Kass [n = 894], Kalma [n = 888], and Muhajiria [n = 896]). A questionnaire detailing access to food and basic services was administered to a subset of households (n = 210 in each site). Main Outcome Measures  Crude and under 5-year mortality rates and nutritional status of IDPs in Kass, Kalma, and Muhajiria, South Darfur. Results  Crude mortality rates, expressed as deaths per 10 000 per day, were 3.2 (95% confidence interval [CI], 2.2-4.1) in Kass, 2.0 (95% CI, 1.3-2.7) in Kalma, and 2.3 (95% CI, 1.2-3.4) in Muhajiria. Under 5-year mortality rates were 5.9 (95% CI, 3.8-8.0) in Kass, 3.5 (95% CI, 1.5-5.7) in Kalma, and 1.0 (95% CI, 0.03-1.9) in Muhajiria. During the period of displacement covered by our survey in Muhajiria, violence was reported to be responsible for 72% of deaths, mainly among young men. Diarrheal disease was reported to cause between 25% and 47% of deaths in camp residents and mainly affected the youngest and oldest age groups. Acute malnutrition was common, affecting 14.1% of the target population in Kass, 23.6% in Kalma, and 10.7% in Muhajiria. Conclusion  This study provides epidemiological evidence of the high rates of mortality and malnutrition among the displaced population in South Darfur and reinforces the need to mount appropriate and timely humanitarian responses.      

Psychophysics, reliability, and norm values for temporal contrast sensitivity implemented on the two alternative forced choice C-Quant device

The current paper describes the design and population testing of a flicker sensitivity assessment technique corresponding to the psychophysical approach for straylight measurement. The purpose is twofold: to check the subjects' capability to perform the straylight test and as a test for retinal integrity for other purposes. The test was implemented in the Oculus C-Quant straylight meter, using homemade software (MATLAB). The geometry of the visual field lay-out was identical, as was the subjects' 2AFC task. A comparable reliability criterion ("unc") was developed. Outcome measure was logTCS (temporal contrast sensitivity). The population test was performed in science fair settings on about 400 subjects. Moreover, 2 subjects underwent extensive tests to check whether optical defects, mimicked with trial lenses and scatter filters, affected the TCS outcome. Repeated measures standard deviation was 0.11 log units for the reference population. Normal values for logTCS were around 2 (threshold 1%) with some dependence on age (range 6 to 85 years). The test outcome did not change upon a tenfold (optical) deterioration in visual acuity or straylight. The test has adequate precision for checking a subject's capability to perform straylight assessment. The unc reliability criterion ensures sufficient precision, also for assessment of retinal sensitivity loss.     

A prospective cohort study to investigate cost-minimisation,of Traditional open,open fAst track recovery and laParoscopic fASt track multimodal management,for surgical patients with colon carcinomas (TAPAS study)

Background

The present developments in colon surgery are characterized by two innovations: the introduction of the laparoscopic operation technique and fast recovery programs such as the Enhanced Recovery After Surgery (ERAS) recovery program. The Tapas-study was conceived to determine which of the three treatment programs: open conventional surgery, open 'ERAS' surgery or laparoscopic 'ERAS' surgery for patients with colon carcinomas is most cost minimizing?

Method/design

The Tapas-study is a three-arm multicenter prospective cohort study.All patients with colon carcinoma, eligible for surgical treatment within the study period in four general teaching hospitals and one university hospital will be included. This design produces three cohorts: Conventional open surgery is the control exposure (cohort 1). Open surgery with ERAS recovery (cohort 2) and laparoscopic surgery with ERAS recovery (cohort 3) are the alternative exposures. Three separate time periods are used in order to prevent attrition bias.Primary outcome parameters are the two main cost factors: direct medical costs (real cost price calculation) and the indirect non medical costs (friction method). Secondary outcome parameters are mortality, complications, surgical-oncological resection margins, hospital stay, readmission rates, time back to work/recovery, health status and quality of life.Based on an estimated difference in direct medical costs (highest cost factor) of 38% between open and laparoscopic surgery (alfa = 0.01, beta = 0.05), a group size of 3×40 = 120 patients is calculated.

Discussion

The Tapas-study is three-arm multicenter cohort study that will provide a cost evaluation of three treatment programs for patients with colon carcinoma, which may serve as a guideline for choice of treatment and investment strategies in hospitals.

Trial registration

ISRCTN44649165.