183 research outputs found
Exploitation of Other Social Amoebae by Dictyostelium caveatum
Dictyostelium amoebae faced with starvation trigger a developmental program during which many cells aggregate and form fruiting bodies that consist of a ball of spores held aloft by a thin stalk. This developmental strategy is open to several forms of exploitation, including the remarkable case of Dictyostelium caveatum, which, even when it constitutes 1/10(3) of the cells in an aggregate, can inhibit the development of the host and eventually devour it. We show that it accomplishes this feat by inhibiting a region of cells, called the tip, which organizes the development of the aggregate into a fruiting body. We use live-cell microscopy to define the D. caveatum developmental cycle and to show that D. caveatum amoebae have the capacity to ingest amoebae of other Dictyostelid species, but do not attack each other. The block in development induced by D. caveatum does not affect the expression of specific markers of prespore cell or prestalk cell differentiation, but does stop the coordinated cell movement leading to tip formation. The inhibition mechanism involves the constitutive secretion of a small molecule by D. caveatum and is reversible. Four Dictyostelid species were inhibited in their development, while D. caveatum is not inhibited by its own compound(s). D. caveatum has evolved a predation strategy to exploit other members of its genus, including mechanisms of developmental inhibition and specific phagocytosis
Review for the generalist: evaluation of low back pain in children and adolescents
Back pain is common in children and adolescents. Most cases of back pain are non-specific and self-limiting. In children and adolescents, pain is usually related to the posterior elements of the spine and disc-related problems are rare. Serious pathology, including malignancy and infection needs to be excluded. Evaluation and management is challenging and requires a thorough history and physical exam, and understanding of the immature skeleton. Diagnostic imaging is useful in the evaluation of a child or adolescent with low back pain and can help guide management. This article will review common causes of back pain in the pediatric population
Measurement and Computation of Movement of Bromide Ions and Carbofuran in Ridged Humic-Sandy Soil
Water flow and pesticide transport in the soil of fields with ridges and furrows may be more complex than in the soil of more level fields. Prior to crop emergence, the tracer bromide ion and the insecticide carbofuran were sprayed on the humic-sandy soil of a potato field with ridges and furrows. Rainfall was supplemented by sprinkler irrigation. The distribution of the substances in the soil profile of the ridges and furrows was measured on three dates in the potato growing season. Separate ridge and furrow systems were simulated by using the pesticide emission assessment at regional and local scales (PEARL) model for pesticide behavior in soil–plant systems. The substances travelled deeper in the furrow soil than in the ridge soil, because of runoff from the ridges to the furrows. At 19 days after application, the peak of the bromide distribution was measured to be in the 0.1–0.2 m layer of the ridges, while it was in the 0.3–0.5 m layer of the furrows. After 65 days, the peak of the carbofuran distribution in the ridge soil was still in the 0.1 m top layer, while the pesticide was rather evenly distributed in the top 0.6 m of the furrow soil. The wide ranges in concentration measured with depth showed that preferential water flow and substance transport occurred in the sandy soil. Part of the bromide ion distribution was measured to move faster in soil than the computed wave. The runoff of water and pesticide from the ridges to the furrows, and the thinner root zone in the furrows, are expected to increase the risk of leaching to groundwater in ridged fields, in comparison with more level fields
Effects of preferred-exercise prescription compared to usual exercise prescription on outcomes for people with non-specific low back pain: a randomized controlled trial [ACTRN12608000524392]
Aggressive juvenile fibromatosis of the paranasal sinuses: case report and brief review
Desmoid fibromatoses are benign, slow growing fibroblastic neoplasms, arising from musculoaponeurotic stromal elements. Desmoids are characterized by local invasion, with a high rate of local recurrence and a tendency to destroy adjacent structures and organs. Desmoid fibromatoses are rare in children, and though they may occur in the head and neck region, are extremely rare in the paranasal sinuses. Here we report a case of extraabdominal desmoid fibromatosis in a seven-year-old boy involving the sphenoid sinus, one of only six published reports of desmoid fibromatosis of the paranasal sinuses. The expansile soft tissue mass eroded the walls of the sphenoid sinus as well as the posterior ethmoid air cells extending cephalad through the base of the skull. We discuss the clinicopathologic features of this lesion, including structural and ultrastructural characteristics, and we review the literature regarding treatment and outcome
Motion style acupuncture treatment (MSAT) for acute low back pain with severe disability: a multicenter, randomized, controlled trial protocol
<p>Abstract</p> <p>Background</p> <p>Acupuncture is widely-used to treat patients with low back pain, despite insufficient evidence of the technique's efficacy for acute back pain. Motion style acupuncture treatment (MSAT) is a non-traditional acupuncture treatment requiring a patient to exercise while receiving acupuncture. In Korea, MSAT is used to reduce musculoskeletal pain and improve functional status. The study aims to evaluate the effect of MSAT on acute low back pain with severe disability.</p> <p>Methods/Design</p> <p>This study is a multicenter, randomized, active-controlled trial with two parallel arms. Participants with acute low back pain and severe functional disability, defined as an Oswestry Disability Index (ODI) value > 60%, will be randomly allocated to the acupuncture group and the nonsteroidal anti-inflammatory drug (NSAID) injection group. The acupuncture group will receive MSAT and the NSAID injection group will receive an intramuscular injection of diclofenac. All procedures will be limited to one session and the symptoms before and after treatment will be measured by assessors blinded to treatment allocation. The primary outcome will be measured at 30 minutes after treatment using the numerical rating scale (NRS) of low back pain while the patient is moving. Secondary outcomes will be measured at 30 minutes after treatment using the NRS of leg pain, ODI, patient global impression of change, range of motion (ROM) of the lumbar spine, and degrees of straight leg raising (SLR). Post-treatment follow-up will be performed to measure primary and secondary outcomes with the exception of ROM and SLR at 2, 4, and 24 weeks after treatment.</p> <p>Discussion</p> <p>The results of this trial will be discussed.</p> <p>Trial Registration</p> <p>ClinicalTrial.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT01315561">NCT01315561</a></p
The relationship between low back pain and leisure time physical activity in a working population of cleaners - a study with weekly follow-ups for 1 year
<p>Abstract</p> <p>Background</p> <p>Low back pain (LBP) and leisure time physical activity (LTPA) are considered to be closely related, and clinical guidelines for the treatment of acute LBP recommend patients stay physically active. However, the documentation for this recommendation is sparse and based on studies involving patient populations. The purpose of the study was (1) to investigate the correlation between LBP and LTPA on a weekly basis over the course of a year in a high-risk group of cleaners; and (2) to investigate if maintaining LTPA during an episode of acute LBP has a positive effect on LBP intensity in the subsequent 4 weeks.</p> <p>Methods</p> <p>188 cleaners consented to participate in a 52-week text message survey about hours of LTPA and intensity of LBP (from 0 to 9) over the previous 7 days. The correlation between LBP and LTPA was calculated by Pearson correlation coefficient. During an episode of acute LBP, a mixed effect logistic regression model was used to investigate whether cleaners who maintain LTPA have a lower pain intensity and higher probability of returning to initial pain intensity within the following four weeks compared with cleaners who decrease LTPA during acute LBP.</p> <p>Results</p> <p>The correlation between weekly LTPA and LBP data was negative, but numerically low (r = -0.069) and statistically insignificant (<it>p </it>= 0.08). Among the 82 cleaners experiencing at least one episode of acute LBP, those maintaining LTPA during an episode of acute LBP did not have a lower pain intensity (average LBP intensity difference between groups of 0.06; 95% confidence interval (95% CI) of -0.417 to 0.539) or higher probability of returning to initial pain level (Odds ratio 1,02; 95% CI of 0.50 to 2.09) in the following four weeks compared with cleaners decreasing LTPA during acute LBP.</p> <p>Conclusions</p> <p>Hours of LTPA and intensity of LBP measured on a weekly basis throughout a year showed no close correlation. Maintaining LTPA during an episode of acute LBP did not result in a positive effect on LBP in the following 4 weeks. Documentation of LTPA recommendations for acute LBP in working populations is still needed.</p
Hippocampal state-dependent behavioral reflex to an identical sensory input in rats.
We examined the local field potential of the hippocampus to monitor brain states during a conditional discrimination task, in order to elucidate the relationship between ongoing brain states and a conditioned motor reflex. Five 10-week-old Wistar/ST male rats underwent a serial feature positive conditional discrimination task in eyeblink conditioning using a preceding light stimulus as a conditional cue for reinforced trials. In this task, a 2-s light stimulus signaled that the following 350-ms tone (conditioned stimulus) was reinforced with a co-terminating 100-ms periorbital electrical shock. The interval between the end of conditional cue and the onset of the conditioned stimulus was 4±1 s. The conditioned stimulus was not reinforced when the light was not presented. Animals successfully utilized the light stimulus as a conditional cue to drive differential responses to the identical conditioned stimulus. We found that presentation of the conditional cue elicited hippocampal theta oscillations, which persisted during the interval of conditional cue and the conditioned stimulus. Moreover, expression of the conditioned response to the tone (conditioned stimulus) was correlated with the appearance of theta oscillations immediately before the conditioned stimulus. These data support hippocampal involvement in the network underlying a conditional discrimination task in eyeblink conditioning. They also suggest that the preceding hippocampal activity can determine information processing of the tone stimulus in the cerebellum and its associated circuits
Minimum detectable and minimal clinically important changes for pain in patients with nonspecific neck pain
<p>Abstract</p> <p>Background</p> <p>The minimal detectable change (MDC) and the minimal clinically important changes (MCIC) have been explored for nonspecific low back pain patients and are similar across different cultural settings. No data on MDC and MCIC for pain severity are available for neck pain patients. The objectives of this study were to estimate MDC and MCIC for pain severity in subacute and chronic neck pain (NP) patients, to assess if MDC and MCIC values are influenced by baseline values and to explore if they are different in the subset of patients reporting referred pain, and in subacute versus chronic patients.</p> <p>Methods</p> <p>Subacute and chronic patients treated in routine clinical practice of the Spanish National Health Service for neck pain, with or without pain referred to the arm, and a pain severity ≥ 3 points on a pain intensity number rating scale (PI-NRS), were included in this study. Patients' own "global perceived effect" over a 3 month period was used as the external criterion. The minimal detectable change (MDC) was estimated by means of the standard error of measurement in patients who self-assess as unchanged. MCIC were estimated by the mean value of change score in patients who self-assess as improved (mean change score, MCS), and by the optimal cutoff point in receiver operating characteristics curves (ROC). The effect on MDC and MCIC of initial scores, duration of pain, and existence of referred pain were assessed.</p> <p>Results</p> <p>658 patients were included, 487 of them with referred pain. MDC was 4.0 PI-NRS points for neck pain in the entire sample, 4.2 for neck pain in patients who also had referred pain, and 6.2 for referred pain. MCS was 4.1 and ROC was 1.5 for referred and for neck pain, both in the entire sample and in patients who also complained of referred pain. ROC was lower (0.5 PI-NRS points) for subacute than for chronic patients (1.5 points). MCS was higher for patients with more intense baseline pain, ranging from 2.4 to 4.9 PI-NRS for neck pain and from 2.4 to 5.3 for referred pain.</p> <p>Conclusion</p> <p>In general, improvements ≤ 1.5 PI-NRS points could be seen as irrelevant. Above that value, the cutoff point for clinical relevance depends on the methods used to estimate MCIC and on the patient's baseline severity of pain. MDC and MCIC values in neck pain patients are similar to those for low back pain and other painful conditions.</p
The long-term effects of naprapathic manual therapy on back and neck pain - Results from a pragmatic randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Back and neck pain are very common, disabling and recurrent disorders in the general population and the knowledge of long-term effect of treatments are sparse. The aim of this study was to compare the long-term effects (up to one year) of naprapathic manual therapy and evidence-based advice on staying active regarding non-specific back and/or neck pain. Naprapathy, a health profession mainly practiced in Sweden, Finland, Norway and in the USA, is characterized by a combination of manual musculoskeletal manipulations, aiming to decrease pain and disability in the neuromusculoskeletal system.</p> <p>Methods</p> <p>Subjects with non-specific pain/disability in the back and/or neck lasting for at least two weeks (n = 409), recruited at public companies in Sweden, were included in this pragmatic randomized controlled trial. The two interventions compared were naprapathic manual therapy such as spinal manipulation/mobilization, massage and stretching, (<it>Index Group</it>), and advice to stay active and on how to cope with pain, provided by a physician (C<it>ontrol Group</it>). Pain intensity, disability and health status were measured by questionnaires.</p> <p>Results</p> <p>89% completed the 26-week follow-up and 85% the 52-week follow-up. A higher proportion in the Index Group had a clinically important decrease in pain (risk difference (RD) = 21%, <it>95% CI: 10-30</it>) and disability (RD = 11%, <it>95% CI: 4-22</it>) at 26-week, as well as at 52-week follow-ups (pain: RD = 17%, <it>95% CI: 7-27 </it>and disability: RD = 17%, <it>95% CI: 5-28</it>). The differences between the groups in pain and disability considered over one year were statistically significant favoring naprapathy (p ≤ 0.005). There were also significant differences in improvement in bodily pain and social function (subscales of SF-36 health status) favoring the Index Group.</p> <p>Conclusions</p> <p>Combined manual therapy, like naprapathy, is effective in the short and in the long term, and might be considered for patients with non-specific back and/or neck pain.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN56954776.</p
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