3,240 research outputs found
A standardised nutritional drink as a test meal for the 13 C mixed triglyceride breath test for pancreatic exocrine insufficiency:A randomised, two-arm crossover comparative study
BACKGROUND: The 13 C mixed triglyceride breath test (13 C MTGT) is a diagnostic test for pancreatic exocrine insufficiency (PEI). It is poorly standardised with much heterogeneity of the test meal, the commonest being toast and butter. A standardised oral nutritional supplement that could be easily transported, stored and made up would be valuable for making this test accessible outside of specialist centres.METHODS: A prospective, randomised, two-arm crossover study of different test meals was carried out in 14 healthy controls. The 13 C MTGT was performed in identical conditions on two separate days. Two test meals were given in random order, either standard (toast and butter) or novel (oral nutritional supplement), with 250 mg of 13 C-labelled mixed triglyceride incorporated. Breath samples were taken postprandially to calculate cumulative percentage dose recovery (cPDR) of 13 C at 6 h.RESULTS: All 14 participants completed both arms of the study with no protocol deviations. The mean cPDR was 39.39% (standard deviation [SD] 5.19) for the standard test meal and 39.93% (SD 5.20) for the novel test meal. A one-way repeated measures analysis of variance (ANOVA) found no significant difference in cPDR between the two meals, F(1, 13) = 0.18, p = 0.68 (minimum detectable difference of 0.81 at 80% power).CONCLUSION: This study demonstrates that a standardised oral nutritional supplement can be used without compromising 13 C recovery. Using this test meal provides a standardised dietary stimulus to the pancreas, avoiding possible variation in quantity of dietary components with other test meals. Further, the ease of use of this method would help establish the 13 C MTGT test more widely.</p
Palmitoylation of Desmoglein 2 Is a Regulator of Assembly Dynamics and Protein Turnover.
Desmosomes are prominent adhesive junctions present between many epithelial cells as well as cardiomyocytes. The mechanisms controlling desmosome assembly and remodeling in epithelial and cardiac tissue are poorly understood. We recently identified protein palmitoylation as a mechanism regulating desmosome dynamics. In this study, we have focused on the palmitoylation of the desmosomal cadherin desmoglein-2 (Dsg2) and characterized the role that palmitoylation of Dsg2 plays in its localization and stability in cultured cells. We identified two cysteine residues in the juxtamembrane (intracellular anchor) domain of Dsg2 that, when mutated, eliminate its palmitoylation. These cysteine residues are conserved in all four desmoglein family members. Although mutant Dsg2 localizes to endogenous desmosomes, there is a significant delay in its incorporation into junctions, and the mutant is also present in a cytoplasmic pool. Triton X-100 solubility assays demonstrate that mutant Dsg2 is more soluble than wild-type protein. Interestingly, trafficking of the mutant Dsg2 to the cell surface was delayed, and a pool of the non-palmitoylated Dsg2 co-localized with lysosomal markers. Taken together, these data suggest that palmitoylation of Dsg2 regulates protein transport to the plasma membrane. Modulation of the palmitoylation status of desmosomal cadherins can affect desmosome dynamics
Lymphoceles following second-look laparotomy for ovarian cancer
In patients treated for ovarian cancer it is crucial to distinguish recurrent malignancy from a benign process. Presented herein is a patient who developed bilateral pelvic lymphoceles following a second-look laparotomy for ovarian cancer. Indications for surgical intervention are discussed and the preferred surgical approach is outlined.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27389/1/0000420.pd
Developmental changes in spinal neuronal properties, motor network configuration, and neuromodulation at free-swimming stages of Xenopus tadpoles
We describe a novel preparation of the isolated brainstem and spinal cord from pro-metamorphic tadpole stages of the South African clawed frog (Xenopus laevis) that permits whole cell patch-clamp recordings from neurons in the ventral spinal cord. Previous research on earlier stages of the same species has provided one of the most detailed understandings of the design and operation of a CPG circuit. Here we have addressed how development sculpts complexity from this more basic circuit. The preparation generates bouts of fictive31 swimming activity either spontaneously or in response to electrical stimulation of the optic tectum, allowing an investigation into how the neuronal properties, activity patterns and neuromodulation of locomotor rhythm generation change during development. We describe an increased repertoire of cellular responses compared to younger larval stages and investigate the cellular level effects of nitrergic neuromodulation as well as the development of a sodium pump-mediated ultra-slow afterhyperpolarisation (usAHP) in these free-swimming larval animals.PostprintPeer reviewe
Effectiveness of the <i>Activate </i>injury prevention exercise programme to prevent injury in schoolboy rugby union
Objective The efficacious Activate injury prevention exercise programme has been shown to prevent injuries in English schoolboy rugby union. There is now a need to assess the implementation and effectiveness of Activate in the applie setting. Methods This quasi-experimental study used a 24-hour time-loss injury definition to calculate incidence (/1000 hours) and burden (days lost/1000 hours) for individuals whose teams adopted Activate (used Activate during season) versus non-adopters. The dose-response relationship of varying levels of Activate adherence (median Activate sessions per week) was also assessed. Player-level rugby exposure, sessional Activate adoption and injury reports were recorded by school gatekeepers. Rate ratios (RR), adjusted by cluster (team), were calculated using backwards stepwise Poisson regression to compare rates between adoption and adherence groups. Results Individuals in teams adopting Activate had a 23% lower match injury incidence (RR 0.77, 95% CI 0.55 to 1.07), 59% lower training injury incidence (RR 0.41, 95% CI 0.17 to 0.97) and 26% lower match injury burden (95% CI 0.46 to 1.20) than individuals on non-adopting teams. Individuals with high Activate adherence (>= 3 sessions per week) had a 67% lower training injury incidence (RR 0.33, 95% CI 0.12 to 0.91) and a 32% lower match injury incidence (RR 0.68, 95% CI 0.50 to 0.92) than individuals with low adherence (<1 session per week). While 65% of teams adopted Activate during the season, only one team used Activate three times per week, using whole phases and programme progressions. Conclusion Activate is effective at preventing injury in English schoolboy rugby. Attention should focus on factors influencing programme uptake and implementation, ensuring Activate can have maximal benefit
Lithium atom interferometer using laser diffraction : description and experiments
We have built and operated an atom interferometer of the Mach-Zehnder type.
The atomic wave is a supersonic beam of lithium seeded in argon and the mirrors
and beam-splitters for the atomic wave are based on elastic Bragg diffraction
on laser standing waves at 671 nm. We give here a detailed description of our
experimental setup and of the procedures used to align its components. We then
present experimental signals, exhibiting atomic interference effects with a
very high visibility, up to 84.5 %. We describe a series of experiments testing
the sensitivity of the fringe visibility to the main alignment defects and to
the magnetic field gradient.Comment: 8 avril 200
Effect of H on the crystalline and magnetic structures of the YCo3-H(D) system. I. YCo3 from neutron powder diffraction and first-principles calculations
This paper reports investigations into the influence of hydrogen on the magnetic properties of the YCo3-H
system. We report results on the magnetic structure and magnetic transitions of YCo3 using a combination of
neutron powder diffraction measurements and first-principles full potential augmented plane wave + local
orbital calculations under the generalized gradient approximation. The ferromagnetic and ferrimagnetic structures
are examined on an equal footing. However, we identify that, no matter which structure is used as the
starting point, the neutron diffraction data always refines down to the ferrimagnetic structure with the Co2
atoms having antiparallel spins. In the ab initio calculations, the inclusion of spin-orbit coupling is found to be
important in the prediction of the correct magnetic ground state. Here, the results suggest that, for zero external
field and sufficiently low temperatures, the spin arrangement of YCo3 is ferrimagnetic rather than ferromagnetic
as previously believed. The fixed spin moment calculation technique has been employed to understand
the two successive field-induced magnetic transitions observed in previous magnetization measurements under
increasing ultrahigh magnetic fields. We find that the magnetic transitions start from the ferrimagnetic phase
�0.61�B/Co� and terminate with the ferromagnetic phase �1.16�B/Co�, while the spin on the Co2 atoms
progressively changes from antiparallel ferrimagnetic to paramagnetic and then to ferromagnetic. Our neutron
diffraction measurements, ab initio calculations, and the high field magnetization measurements are thus
entirely self-consistent
Eight Weeks of Self-Resisted Neck Strength Training Improves Neck Strength in Age-Grade Rugby Union Players:A Pilot Randomized Controlled Trial
BACKGROUND: Greater neck strength is associated with fewer head and neck injuries. Neck-strengthening programs are commonly burdensome, requiring specialist equipment or significant time commitment, which are barriers to implementation. HYPOTHESIS: Completing a neck-strengthening program will increase isometric neck strength in age-group rugby players. STUDY DESIGN: A pilot randomized controlled exercise intervention study. LEVEL OF EVIDENCE: Level 2. METHODS: Twenty-eight U18 (under 18) male regional age-group rugby union players were randomized (intervention n =15/control n = 13). An 8-week exercise program was supervised during preseason at the regional training center. Control players continued their “normal practice,” which did not include neck-specific strengthening exercises. The 3-times weekly trainer-led intervention program involved a series of 15-second self-resisted contractions, where players pushed maximally against their own head, in forward, backward, left, and right directions. OUTCOME MEASURE: Peak isometric neck strength (force N) into neck flexion, extension, and left and right side flexion was measured using a handheld dynamometer. RESULTS: Postintervention between-group mean differences (MDs) in isometric neck strength change were adjusted for baseline strength and favored the intervention for total neck strength (effect size [ES] = 1.2, MD ± 95% CI = 155.9 ± 101.9 N, P = 0.004) and for neck strength into extension (ES = 1.0, MD ± 95% CI = 59.9 ± 45.4 N, P = 0.01), left side flexion (ES = 0.7, MD ± 95% CI = 27.5 ± 26.9 N, P = 0.05), and right side flexion (ES = 1.3, MD ± 95% CI = 50.5 ± 34.4 N, P = 0.006). CONCLUSION: This resource-efficient neck-strengthening program has few barriers to implementation and provides a clear benefit in U18 players’ neck strength. While the present study focused on adolescent rugby players, the program may be appropriate across all sports where head and neck injuries are of concern and resources are limited. CLINICAL RELEVANCE: Greater neck strength is associated with fewer head and neck injuries, including concussion. Performing this neck exercise program independently, or as part of a whole-body program like Activate, an interactive guide for players and coaches, could contribute to lower sports-related head and neck injuries
Prenatal development is linked to bronchial reactivity: epidemiological and animal model evidence
Chronic cardiorespiratory disease is associated with low birthweight suggesting the importance of the developmental environment. Prenatal factors affecting fetal growth are believed important, but the underlying mechanisms are unknown. The influence of developmental programming on bronchial hyperreactivity is investigated in an animal model and evidence for comparable associations is sought in humans. Pregnant Wistar rats were fed either control or protein-restricted diets throughout pregnancy. Bronchoconstrictor responses were recorded from offspring bronchial segments. Morphometric analysis of paraffin-embedded lung sections was conducted. In a human mother-child cohort ultrasound measurements of fetal growth were related to bronchial hyperreactivity, measured at age six years using methacholine. Protein-restricted rats' offspring demonstrated greater bronchoconstriction than controls. Airway structure was not altered. Children with lesser abdominal circumference growth during 11-19 weeks' gestation had greater bronchial hyperreactivity than those with more rapid abdominal growth. Imbalanced maternal nutrition during pregnancy results in offspring bronchial hyperreactivity. Prenatal environmental influences might play a comparable role in humans
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