Postnatal fish oil supplementation increased infant n-3 polyunsaturated fatty acid (PUFA) levels and associated with lowered allergen-specific Th2 responses and elevated polyclonal Th1 responses. Our results add to existing evidence of n-3 PUFA having immunomodulatory properties that are potentially allergy-protective.

The findings suggest a potential role for the use of PKCζ levels in cord blood T cells as a presymptomatic test to predict allergy risk in children, particularly offspring of allergic mothers, and that the basis of this relationship is related to cytokine patterns in mature T cells.

Neoadjuvant (preoperative) chemoradiotherapy (CRT) decreases the risk of rectal cancer recurrence and reduces tumour volume prior to surgery. However, response to CRT varies considerably between individuals and factors associated with response are poorly understood. Foxp3+ regulatory T cells (Tregs) inhibit anti-tumour immunity and may limit any response to chemotherapy and radiotherapy. We have previously reported that a low density of Tregs in the tumour stroma following neoadjuvant CRT for rectal cancer is associated with improved tumour regression. Here we have examined the association between Treg density in pre-treatment diagnostic biopsy specimens and treatment response, in this same patient cohort. We aimed to determine whether pre-treatment tumour-infiltrating Treg density predicts subsequent response to neoadjuvant CRT. Foxp3+, CD8+ and CD3+ cell densities in biopsy samples from 106 patients were assessed by standard immunohistochemistry (IHC) and evaluated for their association with tumour regression grade and survival. We found no association between the density of any T cell subset pre-treatment and clinical outcome, indicating that tumour-infiltrating Treg density does not predict response to neoadjuvant CRT in rectal cancer. Taken together with the findings of the previous study, these data suggest that in the context of neoadjuvant CRT for rectal cancer, the impact of chemotherapy and/or radiotherapy on anti-tumour immunity may be more important than the state of the pre-existing local immune response.

Honey bees are hosts to more than 80 different parasites, some of them being highly virulent and responsible for substantial losses in managed honey bee populations. The study of honey bee pathogens and their interactions with the bees' immune system has therefore become a research area of major interest. Here we developed a fast, accurate and reliable method to quantify the viability of spores of the honey bee gut parasite Nosema apis. To verify this method, a dilution series with 0, 25, 50, 75, and 100% live N. apis was made and SYTO 16 and Propidium Iodide (n 5 35) were used to distinguish dead from live spores. The viability of spores in each sample was determined by flow cytometry and compared with the current method based on fluorescence microscopy. Results show that N. apis viability counts using flow cytometry produced very similar results when compared with fluorescence microscopy. However, we found that fluorescence microscopy underestimates N. apis viability in samples with higher percentages of viable spores, the latter typically being what is found in biological samples. A series of experiments were conducted to confirm that flow cytometry allows the use of additional fluorescent dyes such as SYBR 14 and SYTOX Red (used in combination with SYTO 16 or Propidium Iodide) to distinguish dead from live spores. We also show that spore viability quantification with flow cytometry can be undertaken using substantially lower dye concentrations than fluorescence microscopy. In conclusion, our data show flow cytometry to be a fast, reliable method to quantify N. apis spore viabilities, which has a number of advantages compared with existing methods. V C 2013International Society for Advancement of Cytometry Key terms Nosema apis; viability; fluorescence microscopy; flow cytometry; microsporidia; SYTO 16; SYBR 14; Propidium Iodide; SYTOX Red UNDERSTANDING host-parasite interactions depends on experimental methods that can estimate life history traits of parasites related to fitness. Quantification of these is often crucial to gain detailed insights into the intimate interactions between the parasite and its host and consequently determine the virulence or the damage caused by a parasite. Pathogens can avoid detection or overcome attacks by the host's immune system, so their survival and viability within the host is an important factor to understand the dynamics of initial establishment and consequent progression of an infection. The ability to quantify the viability of specific parasites can have a range of experimental applications to assess the effect of host defences on parasite survival. However, such a technique has applied benefits as well, for example to quantify the effectiveness of treatments on parasites or as biosecurity tools to monitor and limit the spreading of infections. Flow cytometry (FCM) is a technique that has been used in the past to detect and monitor the viability of parasites, for example, to quantify Mycoplasm spore survival in goats and sheep after antibacterial treatment (1)....

An important measure of male quality is sperm viability; i.e., the percentage of live sperm within an ejaculate, as this provides an accurate measure of the number of sperm potentially available for egg fertilization. Sperm viability is often determined by fluorescence microscopy using dyes that differentially stain viable and nonviable sperm, but the technique has a number of limitations. Here, a flow cytometry (FCM) method was developed, which allows the rapid determination of honeybee sperm viability, facilitating high throughput analyses. Using samples with known sperm viabilities, it was found that data obtained from FCM were more accurate and less variable compared with data obtained for the same samples using fluorescence microscopy. It was also found that a previously reported additional population of honeybee sperm found in datasets using FCM is caused by freeze-thawing samples. In conclusion, the method described here allows to quantify sperm viability of honeybees quickly and with high accuracy. This will be of great value for future scientific research and could also be of value to guide future bee breeding programs, given the agricultural importance of honeybees as pollinators. V C 2014 International Society for Advancement of Cytometry Key terms honeybee; sperm; flow cytometry; microscopy; viability; SYBR 14; propidium iodide; liquid nitrogen EJACULATE quality is a fundamentally important reproductive male trait as the number of live sperm available for egg fertilization after being transferred to the female's reproductive tract is a key determinant of male competitiveness, reproductive success, and fitness (1-4). A number of methods have been developed in the past to quantify semen quality, including parameters such as sperm viability, motility, morphology, and total number (5-7). Such inspections are often done microscopically or using machinery in combination with software, capable of simultaneously tracking large numbers of sperm cells within a sample (8). Sperm viability, in particular, has become a key measure for semen quality in recent years, and often refers to the proportion of live sperm in an ejaculate. It is generally quantified by measuring the plasma membrane integrity, as the plasma membrane becomes more permeable in dead sperm and coincides with the loss of motility (9,10) and therefore fertilization capacity. Consequently, assessing sperm viability within ejaculates has become of major interest for the study of reproductive biology as well as for medical research and practices, for example to understand and treat male infertility (11).To determine the proportion of live and dead sperm in a semen sample, a number of dyes have been developed, which allow relatively easy quantification of sperm viability. This approach has been used for a number of different species and for the study of a wide range of different questions (6,(12)(13)(14). SYBR 14 and propidium