Comparison of marker types and map assumptions using Markov chain Monte Carlo-based linkage analysis of COGA data

We performed multipoint linkage analysis of the electrophysiological trait ECB21 on chromosome 4 in the full pedigrees provided by the Collaborative Study on the Genetics of Alcoholism (COGA). Three Markov chain Monte Carlo (MCMC)-based approaches were applied to the provided and re-estimated genetic maps and to five different marker panels consisting of microsatellite (STRP) and/or SNP markers at various densities. We found evidence of linkage near the GABRB1 STRP using all methods, maps, and marker panels. Difficulties encountered with SNP panels included convergence problems and demanding computations.     

Changes in potentiation and timing of sensorimotor transmission after adaptation of a postsynaptic transient outward current in a simulated cortical neuron

How adaptation of a postsynaptic transient outward current might affect the efficacy of sensorimotor transmission was investigated. The transmission signals that were studied were a 5 ms conditioned stimulus (CS) and a 60 ms US drawn from intracellularly recorded, depolarizing postsynaptic potentials (PSPs) elicited in pyramidal neurons of the cat motor cortex by a click CS and a glabella tap US, respectively. SPICE, a program used to analyze electrical circuits, was used to simulate the cortical neuron containing the adaptive outward current. Changes in the magnitude and latency of rise to firing threshold of the PSPs were compared i) after presynaptic augmentation of a CS input in the absence of an adaptive postsynaptic current and ii) after decreasing the magnitude of an adaptive postsynaptic current that was rapidly activated by depolarization. Effects of short (6 ms) and long (24 ms) inactivation time constants of the postsynaptic current were also studied. In both presynaptic adaptation and postsynaptic adaptation, the potentiation of the magnitude of the CS-induced PSP was similar, with the latency to threshold being reduced by < or = 1 ms in both cases. The effects on the US PSP differed. Presynaptic adaptation affecting the CS had no effect on the US. Adaptation of the CS by a postsynaptic outward current with a 6 ms inactivation time constant, reduced the latency to threshold of an EPSP from a nearby US synapse by up to 6 ms by augmenting the initial portion of the slowly rising US-induced PSP. Adaptation of a postsynaptic current with a 24 ms inactivation time constant reduced the latency of response to the US PSP by up to 16 ms. When the US synapse was relocated to the soma, the reduction in US latency caused by adaptation of the outward current at the CS synapse was reduced by up to one half. The latency of slowly rising components of integrated synaptic responses to compound CSs of > 5 ms duration from multiple synaptic inputs would be expected to show reductions corresponding to those of the US. We conclude that potentiation of synaptic transmission by adaptation of a postsynaptic outward current can result in reductions of latency of sensorimotor transmission that can significantly affect the timing and accuracy of controlled motor tasks. These effects depend significantly on the locations of the synaptic inputs within the cell.     

Cleavage efficient 2A peptides for high level monoclonal antibody expression in CHO cells

Linking the heavy chain (HC) and light chain (LC) genes required for monoclonal antibodies (mAb) production on a single cassette using 2A peptides allows control of LC and HC ratio and reduces non-expressing cells. Four 2A peptides derived from the foot-and-mouth disease virus (F2A), equine rhinitis A virus (E2A), porcine teschovirus-1 (P2A) and Thosea asigna virus (T2A), respectively, were compared for expression of 3 biosimilar IgG1 mAbs in Chinese hamster ovary (CHO) cell lines. HC and LC were linked by different 2A peptides both in the absence and presence of GSG linkers. Insertion of a furin recognition site upstream of 2A allowed removal of 2A residues that would otherwise be attached to the HC. Different 2A peptides exhibited different cleavage efficiencies that correlated to the mAb expression level. The relative cleavage efficiency of each 2A peptide remains similar for expression of different IgG1 mAbs in different CHO cells. While complete cleavage was not observed for any of the 2A peptides, GSG linkers did enhance the cleavage efficiency and thus the mAb expression level. T2A with the GSG linker (GT2A) exhibited the highest cleavage efficiency and mAb expression level. Stably amplified CHO DG44 pools generated using GT2A had titers 357, 416 and 600 mg/L for the 3 mAbs in shake flask batch cultures. Incomplete cleavage likely resulted in incorrectly processed mAb species and aggregates, which were removed with a chromatin-directed clarification method and protein A purification. The vector and methods presented provide an easy process beneficial for both mAb development and manufacturing.     

Influence de l'âge des grand-parents sur l'apparition des mâles chez le Rotifère Notommata copeus Ehr.

When parental females (♀♀P = mothers) of the rotifer Notommata copeus are placed in light conditions inducing the appearance of mictic females in their offspring (F₁), the age of the parents of these parental females significantly affects the ratio of mictic females in the F₁ generation.

The preparental females (♀♀PP = grandmothers), the parental females and the F₁ females are isolated in a medium changed at each generation and, in the second experimental series, changed daily: the preparental age effect implicates the transmission of substances on two generations.

This influence of the preparental age is rhythmic: the ratio of mictic females in F₁ related to this age varies in a sinusoidal manner. This influence is endogenous: it persists, always in a sinusoidal form, when the medium in which each grandmother is placed is changed daily.

Furthermore, the net reproduction ratio, Ro, does not vary significantly with the preparental age during these experiments.     

A benefit-finding intervention for family caregivers of persons with Alzheimer disease: study protocol of a randomized controlled trial

Background

Patients with ST-elevation myocardial infarction (STEMI) not treated with primary or rescue percutaneous coronary intervention (PCI) are at risk for recurrent ischemia, especially when viability in the infarct-area is present. Therefore, an invasive strategy with PCI of the infarct-related coronary artery in patients with viability would reduce the occurrence of a composite end point of death, reinfarction, or unstable angina (UA).

Methods

Patients admitted with an (sub)acute myocardial infarction, who were not treated by primary or rescue PCI, and who were stable during the first 48 hours after the acute event, were screened for the study. Eventually, we randomly assigned 216 patients with viability (demonstrated with low-dose dobutamine echocardiography) to an invasive or a conservative strategy. In the invasive strategy stenting of the infarct-related coronary artery was intended with abciximab as adjunct treatment. Seventy-five (75) patients without viability served as registry group. The primary endpoint was the composite of death from any cause, recurrent myocardial infarction (MI) and unstable angina at one year. As secondary endpoint the need for (repeat) revascularization procedures and anginal status were recorded.

Results

The primary combined endpoint of death, recurrent MI and unstable angina was 7.5% (8/106) in the invasive group and 17.3% (19/110) in the conservative group (Hazard ratio 0.42; 95% confidence interval [CI] 0.18-0.96; p = 0.032). During follow up revascularization-procedures were performed in 6.6% (7/106) in the invasive group and 31.8% (35/110) in the conservative group (Hazard ratio 0.18; 95% CI 0.13-0.43; p < 0.0001). A low rate of recurrent ischemia was found in the non-viable group (5.4%) in comparison to the viable-conservative group (14.5%). (Hazard-ratio 0.35; 95% CI 0.17-1.00; p = 0.051).

Conclusion

We demonstrated that after acute MI (treated with thrombolysis or without reperfusion therapy) patients with viability in the infarct-area benefit from a strategy of early in-hospital stenting of the infarct-related coronary artery. This treatment results in a long-term uneventful clinical course. The study confirmed the low risk of recurrent ischemia in patients without viability.

Trial registration

ClinicalTrials.gov: NCT00149591.     

Single-Leaf Resolution of the Temporal Population Dynamics of Aureobasidium pullulans on Apple Leaves

The abundance of phylloplane microorganisms typically varies over several orders of magnitude among leaves sampled concurrently. Because the methods traditionally used to sample leaves are destructive, it has remained unclear whether this high variability is due to fixed differences in habitat quality among leaves or to asynchronous temporal variation in the microbial population density on individual leaves. We developed a novel semidestructive assay to repeatedly sample the same apple leaves from orchard trees over time by removing progressively more proximal ~1-cm-wide transverse segments. Aureobasidium pullulans densities were determined by standard leaf homogenization and plating procedures and were expressed as CFU per square centimeter of segment. The A. pullulans population densities among leaves were lognormally distributed. The variability in A. pullulans population densities among subsections of a given leaf was one-third to one-ninth the variability among whole leaves harvested concurrently. Sequential harvesting of leaf segments did not result in detectable changes in A. pullulans density on residual leaf surfaces. These findings implied that we could infer whole-leaf A. pullulans densities over time by using partial leaves. When this successive sampling regimen was applied over the course of multiple 7- to 8-day experiments, the among-leaf effects were virtually always the predominant source of variance in A. pullulans density estimates. Changes in A. pullulans density tended to be synchronous among leaves, such that the rank order of leaves arrayed with respect to A. pullulans density was largely maintained through time. Occasional periods of asynchrony were observed, but idiosyncratic changes in A. pullulans density did not contribute appreciably to variation in the distribution of populations among leaves. This suggests that persistent differences in habitat (leaf) quality are primarily responsible for the variation in A. pullulans density among leaves in nature.     

Antigen-specific helper factor reacts with antibodies to human beta 2 microglobulin

Antigen-specific helper factor was induced in vitro from lymphoid cells of monkeys and mice by using an antigen derived from Streptococcus mutans. Helper activity was removed from supernatants of monkey cells by affinity chromatography on Sepharose 4B insolubilized antibodies specific for human beta 2-microglobulin (H beta 2M) prepared in chicken, rabbit and rat, and an insolubilized monoclonal mouse anti-H beta 2M antibody-bound monkey helper factor activity. However, guinea pig antibody to human beta 2M was inactive. In parallel studies, the pattern of absorption of mouse helper factor (HF) was different from that of the monkey in that insolubilized guinea pig anti-H beta 2M bound helper factor, whereas rabbit and monoclonal anti-H beta 2M failed to do so. Although these findings were not compatible with an intact beta 2M chain being present in helper factor, they may imply a cross-reactivity of beta 2M with a "constant region" of helper factor that may share common sequences with beta 2M. This may suggest that factor genes have evolved from the same ancestral genes as beta 2M.     

Induction of multiple ovulation in the cow with single injections of FSH and HCG.

A gonadotrophin regimen was developed to induce a high incidence of double and triple ovulations in the beef cow using a single injection of FSH on Day 16 followed by a low dose of HCG on the day of oestrus. Conception rate was not affected by gonadotrophin treatment and 1/9 cows experiencing multiple ovulations gave birth to twin calves.