A single amino acid (Asp159) from the dog prion protein suppresses the toxicity of the mouse prion protein in Drosophila

Misfolding of the prion protein (PrP) is the key step in the transmission of spongiform pathologies in humans and several animals. Although PrP is highly conserved in mammals, a few changes in the sequence of endogenous PrP are proposed to confer protection to dogs, which were highly exposed to prion during the mad-cow epidemics. D159 is a unique amino acid found in PrP from dogs and other canines that was shown to alter surface charge, but its functional relevance has never been tested in vivo. Here, we show in transgenic Drosophila that introducing the N159D substitution on mouse PrP decreases its turnover. Additionally, mouse PrP-N159D demonstrates no toxicity and accumulates no pathogenic conformations, suggesting that a single D159 substitution is sufficient to prevent PrP conformational change and pathogenesis. Understanding the mechanisms mediating the protective activity of D159 is likely to lessen the burden of prion diseases in humans and domestic animals.

Scalable photonic network architecture based on motional averaging in room temperature gas

Quantum interfaces between photons and atomic ensembles have emerged as powerful tools for quantum technologies. Efficient storage and retrieval of single photons requires long-lived collective atomic states, which is typically achieved with immobilized atoms. Thermal atomic vapours, which present a simple and scalable resource, have only been used for continuous variable processing or for discrete variable processing on short timescales where atomic motion is negligible. Here we develop a theory based on motional averaging to enable room temperature discrete variable quantum memories and coherent single-photon sources. We demonstrate the feasibility of this approach to scalable quantum memories with a proof-of-principle experiment with room temperature atoms contained in microcells with spin-protecting coating, placed inside an optical cavity. The experimental conditions correspond to a few photons per pulse and a long coherence time of the forward scattered photons is demonstrated, which is the essential feature of the motional averaging.

Population pharmacokinetics of plasma-derived factor IX: procedures for dose individualization

BACKGROUND

Population pharmacokinetic (POPPK) models describing factor IX (FIX) activity levels in plasma, in combination with individual FIX measurements, may be used to individualize dosing in the treatment of hemophilia B.

OBJECTIVES

The aim was to reevaluate a previously developed POPPK model for FIX activity and to explore the number and timing of FIX samples required in pharmacokinetic (PK) dose individualization.

METHODS

The POPPK model was reevaluated using an extended data set. Several sampling schedules, varying with respect to the timing and number of samples, were evaluated in a simulation study with relative dose errors compared between schedules. The performance of individually calculated doses was compared with commonly prescribed FIX doses with respect to the number of patients with a trough FIX activity > 0.01 U mL(-1) .

RESULTS AND CONCLUSIONS

A three-compartment PK model best described the FIX activity levels. The number and timing of samples greatly influenced imprecision in dose prediction. Schedules with single samples taken on both day 2 and day 3 were identified as being convenient schedules with an acceptable performance level. Individually calculated doses performed better with respect to patient target attainment than a fixed 40 U kg(-1) dose regardless of how many samples were available to calculate individual doses. The results of this study suggest that PK dose tailoring with limited sampling may be applicable for plasma-derived FIX products.

Macronutrient intake regulates sexual conflict in decorated crickets

Sexual conflict results in a diversity of sex-specific adaptations, including chemical additions to ejaculates. Male decorated crickets (Gryllodes sigillatus) produce a gelatinous nuptial gift (the spermatophylax) that varies in size and free amino acid composition, which influences a female's willingness to fully consume this gift. Complete consumption of this gift maximizes sperm transfer through increased retention of the sperm-containing ampulla, but hinders post-copulatory mate choice. Here, we examine the effects of protein (P) and carbohydrate (C) intake on the weight and amino acid composition of the spermatophylax that describes its gustatory appeal to the female, as well as the ability of this gift to regulate sexual conflict via ampulla attachment time. Nutrient intake had similar effects on the expression of these traits with each maximized at a high intake of nutrients with a P : C ratio of 1 : 1.3. Under dietary choice, males actively regulated their nutrient intake but this regulation did not coincide with the peak of the nutritional landscape for any trait. Our results therefore demonstrate that a balanced intake of nutrients is central to regulating sexual conflict in G. sigillatus, but males are constrained from reaching the optima needed to bias the outcome of this conflict in their favour.

Meta-analysis of reconstruction techniques after low anterior resection for rectal cancer

BACKGROUND

Options for reconstruction after low anterior resection (LAR) for rectal cancer include straight or side-to-end coloanal anastomosis (CAA), colonic J pouch and transverse coloplasty. This systematic review compared these techniques in terms of function, surgical outcomes and quality of life.

METHODS

A systematic literature search (MEDLINE, Embase and the Cochrane Library, from inception of the databases until November 2014) was conducted to identify randomized clinical trials comparing reconstructive techniques after LAR. Random-effects meta-analyses were carried out, and results presented as weighted odds ratios or mean differences with corresponding 95 per cent c.i. A network meta-analysis was conducted for the outcome anastomotic leakage.

RESULTS

The search yielded 965 results; 21 trials comprising data from 1636 patients were included. Colonic J pouch was associated with lower stool frequency and antidiarrhoeal medication use for up to 1 year after surgery compared with straight CAA. Transverse coloplasty and side-to-end CAA had similar functional outcomes to the colonic J pouch. No superiority was found for any of the techniques in terms of anastomotic leak rate.

CONCLUSION

Colonic J pouch and side-to-end CAA or transverse coloplasty lead to a better functional outcome than straight CAA for the first year after surgery.

Chimerism, graft survival, and withdrawal of immunosuppressive drugs in HLA matched and mismatched patients after living donor kidney and hematopoietic cell transplantation

Thirty-eight HLA matched and mismatched patients given combined living donor kidney and enriched CD34(+) hematopoietic cell transplants were enrolled in tolerance protocols using posttransplant conditioning with total lymphoid irradiation and anti-thymocyte globulin. Persistent chimerism for at least 6 months was associated with successful complete withdrawal of immunosuppressive drugs in 16 of 22 matched patients without rejection episodes or kidney disease recurrence with up to 5 years follow up thereafter. One patient is in the midst of withdrawal and five are on maintenance drugs. Persistent mixed chimerism was achieved in some haplotype matched patients for at least 12 months by increasing the dose of T cells and CD34(+) cells infused as compared to matched recipients in a dose escalation study. Success of drug withdrawal in chimeric mismatched patients remains to be determined. None of the 38 patients had kidney graft loss or graft versus host disease with up to 14 years of observation. In conclusion, complete immunosuppressive drug withdrawal could be achieved thus far with the tolerance induction regimen in HLA matched patients with uniform long-term graft survival in all patients.

Prophylactic Swallowing Exercises in Head and Neck Cancer Radiotherapy

Many head and neck cancer (HNC) survivors experience reduced quality of life due to radiotherapy (RT)-related dysphagia. The aim of this prospective randomized trial was to evaluate the impact of prophylactic swallowing exercises on swallowing-related outcomes in HNC patients treated with curative RT. Patients treated with primary RT for HNC were candidates for this randomized protocol. Participants in the exercise group were instructed to perform swallowing exercises at home. Participants in the control group were given standard care. Patients were evaluated with modified barium swallow and several other secondary outcome measures at four and nine different time points, respectively. Data were analyzed according to intention-to-treat analyses. A total of 44 consecutive patients were included; 22 in each group. In general, there was no difference between the two groups regarding any of the dysphagia outcomes during and after treatment. Adherence to exercises was poor and dropouts due to especially fatigue were very frequent in both groups. Systematic swallowing exercises had no impact on swallowing outcomes within the first year after RT. Despite repeated supervised sessions, adherence to exercises was a major issue and dropouts were frequent in both the intervention and control group.

Immunolocalization of human alpha-synuclein in the Thy1-aSyn ("Line 61") transgenic mouse line

Alpha-synuclein (a-syn) is the major component of the intracytoplasmic inclusions known as Lewy bodies (LB), which constitute the hallmark of Parkinson's disease (PD). Mice overexpressing human a-syn under the Thy-1 promoter (ASO) show slow neurodegeneration and some behavioral deficits similar to those seen in human PD patients. Here, we describe a whole-brain distribution of human a-syn in adult ASO mice. We find that the human a-syn is ubiquitously distributed in the brain including the cerebellar cortex, but the intensity and sub-cellular localization of the staining differed in the various regions of the central nervous system. Among particular CNS areas with human a-syn immunoreactivity, we describe staining patterns in the olfactory bulb, cortex, hippocampus, thalamic region, brainstem nuclei and cerebellar cortex. This immunohistochemical study provides an anatomical map of the human a-syn distribution in ASO mice. Our data show that human a-syn, although not present at levels that were detectable by immunostaining in dopaminergic neurons of substantia nigra or noradrenergic neurons of locus coeruleus, was highly expressed in other PD relevant regions of the brain in different neuronal subtypes. These data will help to relate a-syn expression to the phenotypic manifestations observed in this widely used mouse line.