Variability and Impact of Self-Selected Interset Rest Periods During Experienced Strength Training.

We investigated the variability of strength trained athletes' self-selected rest periods between sets of heavy squat training. Sixteen strength-trained male athletes (Mage = 23, SD = 3 years) completed two squat training sessions 48 hours apart. Each training session consisted of five sets of 5RM squats, interspersed with self-selected interset rest periods. A Gymaware linear optical encoder collected kinetic data for each squat and temporal data for each interset rest period. The participants' subjective ratings of the experience were taken before (Readiness to Lift [RTL]) and after (Rating of Perceived Effort [RPE]) each set. Mean total rest time and mean power output differed significantly between sessions. For both sessions, interset rest period increased, and power output decreased between Sets 3, 4, and 5 (95% CI range [-101, -17]) compared with Set 1. In both sessions, RPE increased significantly in Set 3 compared with Set 1 (95% CI range = [0.68, 2.19]), while RTL decreased significantly from Set 3 (95% CI range [-2.99, -0.58]) compared to Set 1. Interset rest period and power output demonstrated fair reliability between sessions (mean intraclass correlation coefficient = 0.55), while RPE and RTL demonstrated good and excellent reliability, respectively (mean intraclass correlation coefficient = 0.63 and 0.80). In conclusion, highly trained strength athletes demonstrated a significant difference in their between session power output and total rest time when using self-selected interset rest periods, despite stability in their subjective ratings of fatigue and effort. Interset rest periods can be self-selected reliably to complete strength training in heavy squat protocol; however, power output may decline during the set.

How many squat-stand manoeuvres to assess dynamic cerebral autoregulation?

PURPOSE: Squat-stand manoeuvres (SSMs) have been used to induce blood pressure (BP) changes for the reliable assessment of dynamic cerebral autoregulation. However, they are physically demanding and thus multiple manoeuvres can be challenging for older subjects. This study aimed to determine the minimum number of SSMs required to obtain satisfactory coherence, thus minimising the subjects' workload. METHOD: 20 subjects performed SSMs at a frequency of 0.05 Hz. End-tidal CO2, cerebral blood flow velocity, heart rate, continuous BP and the depth of the squat were measured. 11 subjects returned for a repeat visit. The time points at which subjects had performed 3, 6, 9, 12 and 15 SSMs were determined. Transfer function analysis was performed on files altered to the required length to obtain estimates of coherence and the autoregulation index (ARI). RESULTS: After three SSMs, coherence (0.05 Hz) was 0.93 ± 0.05, and peaked at 0.95 ± 0.02 after 12 manoeuvres. ARI decreased consecutively with more manoeuvres. ARI was comparable across the two visits (p = 0.92), but coherence was significantly enhanced during the second visit (p < 0.01). The intra-subject coefficients of variation (CoV) for ARI remained comparable as the number of manoeuvres varied. CONCLUSIONS: This analysis can aid those designing SSM protocols, especially where participants are unable to tolerate a standard 5-min protocol or when a shorter protocol is needed to accommodate additional tests. We emphasise that fewer manoeuvres should only be used in exceptional circumstances, and where possible a full set of manoeuvres should be performed. Furthermore, these results need replicating at 0.10 Hz to ensure their applicability to different protocols.

Comparison of patient (POEM), observer (EASI, SASSAD, TIS) and corneometry measures of emollient effectiveness in children with eczema: findings from the COMET feasibility trial.

BACKGROUND: Eczema affects around 20% of children, but multiple different outcome measures have hampered research into the effectiveness of different treatments. OBJECTIVES: To compare the change in scores and correlations within and between five measures of eczema severity: Patient-Orientated Eczema Measure (POEM), Eczema Area and Severity Index (EASI), Six Area, Six Sign Atopic Dermatitis (SASSAD), Three Item Severity (TIS) and skin hydration (corneometry). METHODS: Data from a feasibility trial that randomized young children with eczema to one of four emollients were used. Participants were followed for 3 months (84 days). Descriptive statistics (by emollient over time) and Spearman's correlation coefficients comparing scores at each time point and absolute change (between adjacent time points) for each outcome measure were calculated. RESULTS: In total, 197 children, mean ± SD age 21·7 ± 12·8 months, were randomized. POEM and TIS appeared to capture a range of eczema severity at baseline, but only POEM had close approximation to normal distribution. Mean POEM, EASI, SASSAD and TIS scores improved month by month, with POEM showing the greatest sensitivity (effect size 0·42). Correlations within POEM, EASI, SASSAD and TIS were moderate to good, decreasing over time. Correlations between measures were strongest for EASI, SASSAD and TIS. By contrast, corneometry scores were more variable, correlated less well over time and were poorly correlated with the other measures. CONCLUSIONS: Except for corneometry, all measures appear to change in relation to emollient use over time and correlate well with themselves. POEM demonstrated the greatest range of scores at baseline and change in eczema severity over the first 28 days.

Meeting and greeting in the clinical setting - are we doing what patients want?

Objective To determine how patients want to be greeted by clinicians on a first encounter in the clinical setting.Setting A UK dental teaching hospital in 2015/16.Materials and methods Data was collected prospectively via 450 patient questionnaires. The results were stratified by generational cohort and compared to assess if there was an association between patient preferences and the generational theory.Results Patients preferred to be greeted informally by their first name and didn't mind how the clinician introduced themselves or preferred them to use their first name also. Patients showed a preference to shake hands with their clinician, particularly in older generational cohorts. The majority of patients believed that it was helpful to know the training grade of the clinician providing treatment but didn't understand what the different grades meant. Patients believed that explaining the different training grades and using colour-coded uniforms would be useful.Conclusions Consideration should be given to addressing patients informally by their first name and shaking hands at a first encounter. Clinicians should routinely disclose their training grade when introducing themselves and consideration should be given to providing patients with an explanation of the different training grades and using colour-coded uniforms to avoid confusion.

Building scientific confidence in the development and evaluation of read-across.

Read-across is an alternative approach exploited to address information requirements for risk assessment and for regulatory programmes such as the European Union's REACH regulation. Whilst read-across approaches are accepted in principle, difficulties still remain in applying them consistently in practice. Recent work within Cefic LRI and ECETOC attempted to summarize the state-of-the-art and identify some of the barriers to broader acceptance of read-across approaches to overcome these. Acceptance is undoubtedly thwarted partly by the lack of a systematic framework to characterize the read-across justification and identify the uncertainties particularly for complex regulatory endpoints such as repeated-dose toxicity or prenatal developmental toxicity. Efforts are underway by the European Chemical's Agency (ECHA) to develop a Read-Across Assessment Framework (RAAF) and private sector experts have also considered the development of a similar framework. At the same time, mechanistic chemical categories are being proposed which are underpinned by Adverse Outcome Pathways (AOPs). Currently such frameworks are only focusing on discrete organic substances, though the AOP approach could conceivably be applied to evaluate more complex substances such as mixtures. Here we summarize the deliberations of the Cefic LRI read-across team in characterizing scientific confidence in the development and evaluation of read-across.

A laboratory-based hard x-ray monochromator for high-resolution x-ray emission spectroscopy and x-ray absorption near edge structure measurements.

We report the development of a laboratory-based Rowland-circle monochromator that incorporates a low power x-ray (bremsstrahlung) tube source, a spherically bent crystal analyzer, and an energy-resolving solid-state detector. This relatively inexpensive, introductory level instrument achieves 1-eV energy resolution for photon energies of ∼5 keV to ∼10 keV while also demonstrating a net efficiency previously seen only in laboratory monochromators having much coarser energy resolution. Despite the use of only a compact, air-cooled 10 W x-ray tube, we find count rates for nonresonant x-ray emission spectroscopy comparable to those achieved at monochromatized spectroscopy beamlines at synchrotron light sources. For x-ray absorption near edge structure, the monochromatized flux is small (due to the use of a low-powered x-ray generator) but still useful for routine transmission-mode studies of concentrated samples. These results indicate that upgrading to a standard commercial high-power line-focused x-ray tube or rotating anode x-ray generator would result in monochromatized fluxes of order 10(6)-10(7) photons/s with no loss in energy resolution. This work establishes core technical capabilities for a rejuvenation of laboratory-based hard x-ray spectroscopies that could have special relevance for contemporary research on catalytic or electrical energy storage systems using transition-metal, lanthanide, or noble-metal active species.

Assessment of the genotoxicity of trichloroethylene in the in vivo micronucleus assay by inhalation exposure.

The in vivo genotoxic potential of trichloroethylene (TCE) was evaluated by examining the incidence of micronucleated polychromatic erythrocytes (MN-PCEs) in the bone marrow. Groups of male CD rats were exposed by inhalation to targeted concentrations of 0 (negative control), 50, 500, 2500 or 5000 ppm for 6 consecutive hours on a single day. The exposure concentrations were selected to overlap those employed by a published study that reported a 2- to 3-fold increase in the frequency of micronuclei in male rats following a single inhalation exposure to 5, 500 and 5000 ppm TCE for 6h but not following repeated exposure to similar concentrations. In addition, any treatment-related findings were assessed in the context of potential TCE-induced hypothermia. Clinical signs consistent with marked TCE-induced sedation were observed in rats exposed to 5000 ppm and subsequently three rats died prior to the end of the 6h exposure period. No remarkable changes in body temperature were observed in surviving animals monitored with transponders before and after exposures. There were no statistically significant increases in the frequencies of MN-PCEs in groups treated with the test material as compared to the negative controls. The positive control animals showed a significant increase in the frequency of MN-PCEs and a decrease in the relative proportion of PCEs among erythrocytes as compared to the negative control animals. There were no statistically significant differences in the per cent PCEs in groups treated with the test material. As no increase in the incidence of micronuclei was observed in any of the TCE exposure groups, kinetochore analyses were not performed. Under the experimental conditions used, TCE was considered to be negative in the rat bone marrow micronucleus test.

The structural basis of differential DNA sequence recognition by restriction-modification controller proteins.

Controller (C) proteins regulate the expression of restriction-modification (RM) genes in a wide variety of RM systems. However, the RM system Esp1396I is of particular interest as the C protein regulates both the restriction endonuclease (R) gene and the methyltransferase (M) gene. The mechanism of this finely tuned genetic switch depends on differential binding affinities for the promoters controlling the R and M genes, which in turn depends on differential DNA sequence recognition and the ability to recognize dual symmetries. We report here the crystal structure of the C protein bound to the M promoter, and compare the binding affinities for each operator sequence by surface plasmon resonance. Comparison of the structure of the transcriptional repression complex at the M promoter with that of the transcriptional activation complex at the R promoter shows how subtle changes in protein-DNA interactions, underpinned by small conformational changes in the protein, can explain the molecular basis of differential regulation of gene expression.

Development of PK- and PBPK-based modeling tools for derivation of biomonitoring guidance values.

There are numerous programs ongoing to analyze environmental exposure of humans to xenobiotic chemicals via biomonitoring measurements (e.g.: EU ESBIO, COPHES; US CDC NHANES; Canadian Health Measures Survey). The goal of these projects is to determine relative trends in exposure to chemicals, across time and subpopulations. Due to the lack of data, there is often little information correlating biomarker concentrations with exposure levels and durations. As a result, it can be difficult to utilize biomonitoring data to evaluate if exposures adhere to or exceed hazard/exposure criteria such as the Derived No-Effect Level values under the EU REACH program, or Reference Dose/Concentration values of the US EPA. A tiered approach of simple, arithmetic pharmacokinetic (PK) models, as well as more standardized mean-value, physiologically-based (PBPK) models, have therefore been developed to estimate exposures from biomonitoring results. Both model types utilize a user-friendly Excel spreadsheet interface. QSPR estimations of chemical-specific parameters have been included, as well as accommodation of variations in urine production. Validation of each model's structure by simulations of published datasets and the impact of assumptions of major model parameters will be presented.

Recognition of dual symmetry by the controller protein C.Esp1396I based on the structure of the transcriptional activation complex.

The controller protein C.Esp1396I regulates the timing of gene expression of the restriction-modification (RM) genes of the RM system Esp1396I. The molecular recognition of promoter sequences by such transcriptional regulators is poorly understood, in part because the DNA sequence motifs do not conform to a well-defined symmetry. We report here the crystal structure of the controller protein bound to a DNA operator site. The structure reveals how two different symmetries within the operator are simultaneously recognized by the homo-dimeric protein, underpinned by a conformational change in one of the protein subunits. The recognition of two different DNA symmetries through movement of a flexible loop in one of the protein subunits may represent a general mechanism for the recognition of pseudo-symmetric DNA sequences.

An assessment of the reliability and standardisation of tests used to elicit reference muscular actions for electromyographical normalisation.

Prior to implementing a normalisation method, the standardisation and reliability of the method needs to be examined. This investigation aimed to assess the reliability of EMG amplitudes and test outputs from proposed normalisation methods for the triceps surae. Sixteen participants completed isometric (maximum and sub-maximum); isokinetic (1.05rad/s, 1.31rad/s and 1.83rad/s) squat jump and 20m sprint conditions, on 3 separate occasions over 1week. The EMG data was collected from the medial and lateral gastrocnemius (MG and LG) and soleus (SOL). Log transformed typical error measurements (TEM(CV%)) assessed EMG signal and test output reliability across the three sessions. Only the squat jump provided acceptable EMG reliability for all muscles both between days (SOL: 13%; MG: 14.5%; LG: 11.8%) and between weeks (SOL: 14.5%; MG: 12.9%; LG: 8.9%), with the sprint only showing poor reliability in the LG between days (16.3%). Acceptable reliability for the isometric and isokinetic conditions were muscle and re-test period dependant. Reliable output was found for the squat jump (4.1% and 3.6%), sprint (0.8% and 0.6%) and 1RM plantar flexion test (2.8% and 3.5%) between days and weeks, respectively. Isokinetic plantar flexion displayed poor reliability at all velocities between days and weeks. It was concluded that the squat jump provides a standardised and reproducible reference EMG value for the triceps surae for use as a normalisation method.

Structure of the restriction-modification controller protein C.Esp1396I.

The controller protein of the Esp1396I restriction-modification (R-M) system binds differentially to three distinct operator sequences upstream of the methyltransferase (M) and endonuclease (R) genes to regulate the timing of gene expression. The crystal structure of a complex of the protein with two adjacent operator DNA sequences has been reported; however, the structure of the free protein has not yet been determined. Here, the crystal structure of the free protein is reported, with seven dimers in the asymmetric unit. Two of the 14 monomers show an alternative conformation to the major conformer in which the side chains of residues 43-46 in the loop region flanking the DNA-recognition helix are displaced by up to 10 A. It is proposed that the adoption of these two conformational states may play a role in DNA-sequence promiscuity. The two alternative conformations are also found in the R35A mutant structure, which is otherwise identical to the native protein. Comparison of the free and bound protein structures shows a 1.4 A displacement of the recognition helices when the dimer is bound to its DNA target.

Identification of chicken enterovirus-like viruses, duck hepatitis virus type 2 and duck hepatitis virus type 3 as astroviruses.

Earlier work identified and biologically characterized antigenically distinct enterovirus-like viruses (ELVs) of chickens. Three of these ELVs can now be identified as astroviruses. Characterization involved the use of a hitherto undescribed, degenerate primer-based reverse transcription-polymerase chain reaction (RT-PCR) to amplify astrovirus open reading frame (ORF) 1b-specific cDNA fragments followed by nucleotide sequence determination and analysis of the amplified fragments. ELV-1 was confirmed as an isolate of the astrovirus avian nephritis virus (ANV). ELV-4 (isolate 612) and ELV-3 (isolates FP3 and 11672) were antigenically and genetically related to the second characterized astrovirus of chickens, namely chicken astrovirus (CAstV). Using indirect immunofluorescence, the FP3 and 11672 ELV-3 isolates were very closely related to one another, and less closely related to ELV-4 and the previously described CAstV (P22 18.8.00 reference isolate). Comparative analyses based on the ORF 1b amplicon sequences showed that the FP3 and 11672 ELV-3 isolates shared high nucleotide (95%) and amino acid (98%) identities with one another, and lower nucleotide (76% to 79%) and amino acid (84% to 85%) identity levels with ELV-4 and the reference CAstV P22 18.8.00 isolates. The combined degenerate primer RT-PCR and sequencing methods also provided a nucleotide sequence specific to duck hepatitis virus type 2 (DHV-2) (renamed duck astrovirus) and duck hepatitis virus type 3 (DHV-3), which, for the first time, can also be identified as an astrovirus. Phylogenetic analyses based on the amplified ORF 1b sequences showed that ANV was the most distantly related avian astrovirus, with DHV-3 being more closely related to turkey astrovirus type 2 than DHV-2.

Cutaneous changes in fibrous hamartoma of infancy.

BACKGROUND: Fibrous hamartoma of infancy (FHI) is a fast growing soft tissue tumor that usually arises in the first 2 years of life. The histology of the lesion has been well described. Few studies, however, have looked at changes in the overlying skin and its appendages. METHODS: A database search performed at British Columbia Children's Hospital yielded 15 cases of unequivocal FHI occurring in 12 patients (three were recurrences). Of these, we were able to retrieve 13. Five of 13 cases had sections including epidermis. These slides were reviewed with specific emphasis on skin adnexae. RESULTS: Of the cases with excised epidermis in continuity with the lesion, 5/5 had eccrine changes, including hyperplasia, duct dilatation, intraluminal papillary formations, and squamous syringometaplasia. One case showed epidermal basaloid follicular hyperplasia. CONCLUSIONS: This study shows that eccrine changes are frequently seen in cases of FHI when overlying skin is sampled. This may be a useful clue to consider this diagnosis, especially when the biopsy is superficial.

Detection of pigeon circovirus in cloacal swabs: implications for diagnosis, epidemiology and control.

Pigeon circovirus (picv) was detected in cloacal swab samples by means of a newly-developed, sensitive pcr. An initial investigation of 17 Belgian racing pigeons aged up to eight months showed that rates of detection of 88 per cent and above were achieved using samples of cloacal swab, blood and bursa of Fabricius. The sampling of 15 caged pigeons six times when they were from three to 31 weeks of age indicated that picv infections were more readily detected in cloacal swabs than in blood, and that the virus could be detected in cloacal swabs for longer periods after infection than in blood. picv infections were detected in cloacal swabs from 38 of 47 young pigeons aged from two to 31 weeks, from 12 racing lofts, which had clinical signs including diarrhoea and weight loss, regurgitation and respiratory signs. Samples from birds from two infected lofts indicated that picv could be detected in some birds for at least 27 weeks. Although nine of 14 pigeons aged from 32 to 45 weeks were virus-positive, picv was detected in only one of 18 adult pigeons that originated from four infected lofts.

Development and evaluation of a one-step real-time reverse transcription polymerase chain reaction assay for the detection of salmonid alphaviruses in serum and tissues.

We designed 4 primer pairs to amplify conserved regions of the E1 or nsP4 genes of salmonid alphavirus (SAV) and evaluated their performance in optimized 1-step SYBR green real-time RT-PCR (RRT-PCR) assays. A single primer pair, amplifying a 227 bp segment of E1 was then chosen for further study. This RRT-PCR was shown to be highly repeatable and reproducible over a wide range of RNA dilutions, with a linear relationship between cycle threshold (Ct) value and RNA concentration over a 10(7) dilution range. The limit of detection was calculated to be < or = 1.5 TCID50 ml(-1). When applied to sera previously screened by virus isolation for SAV viraemia, the RRT-PCR correctly identified all 13 culture-positive samples, as well as finding an additional 28 sera positive. Relative semi-quantitation of sera showed a very highly significant relationship between copy number and TCID50 (p < 0.001, R2 = 0.9563). Following experimental infection of salmon, heart samples were consistently positive until 21 d post infection (dpi), with (weak) positive signals still detectable in 50% of fish 70 dpi.

Virological and serological evidence of bovine herpesvirus type 4 in cattle in Northern Ireland.

Bovine herpesvirus type 4 (BHV-4), a member of the genus Rhadinovirus, subfamily Gammaherpesvirinae, within the family Herpesviridae, was isolated in fetal bovine lung cells from samples of vaginal discharge taken from a dairy herd in which approximately 50 per cent of the cattle developed metritis after calving. The identity of the isolate was confirmed by immunofluorescent staining with a BHV-4-specific monoclonal antibody and partial sequencing of a portion of the glycoprotein B gene. Serological testing failed to demonstrate a significant association between the exposure of the cattle to BHV-4 and the metritis, but several cattle seroconverted during the periparturient period, consistent with the recrudescence and shedding of virus associated with the stresses of parturition and the onset of lactation. Despite the previous failure to detect BHV-4 in Northern Ireland, a serological survey of 999 cattle in 49 dairy herds and 51 beef herds found widespread evidence of exposure: 29 of the dairy herds and 35 of the beef herds contained one or more seropositive cattle, and 33.3 per cent of the dairy cattle and 23.3 per cent of the beef cattle were positive.