Abstract Infantile spasms are seizures manifesting within a spectrum of epileptic encephalopathies of infancy that often lead to cognitive impairment. Their current therapies, including ...adrenocorticotropic hormone (ACTH), high dose steroids, or vigabatrin, are not always effective and may be associated with serious side effects. Overactivation of the TORC1 complex of the mTOR pathway is implicated in the pathogenesis of certain genetic and acquired disorders that are linked with infantile spasms, like tuberous sclerosis. Here, we tested the therapeutic potential of rapamycin, a TORC1 inhibitor, as a potential treatment for infantile spasms in the multiple-hit rat model of ACTH-refractory symptomatic infantile spasms, which is not linked to tuberous sclerosis. Rapamycin or vehicle was given after spasms appeared. Their effects on spasms, other seizures, performance in Barnes maze, and expression of the phosphorylated S6 ribosomal protein (pS6: a TORC1 target) in the cortex, using immunofluorescence, were compared. Rapamycin suppressed spasms dose-dependently and improved visuospatial learning, although it did not reduce the frequency of other emerging seizures. High-dose pulse rapamycin effected acute and sustained suppression of spasms and improved cognitive outcome, without significant side effects. Therapeutically effective rapamycin doses normalized the pS6 expression, which was increased in perilesional cortical regions of pups with spasms. These findings support that pathological overactivation of TORC1 may be implicated in the pathogenesis of infantile spasms, including those that are not linked to tuberous sclerosis. Furthermore, a high-dose, pulse rapamycin treatment is a promising, well tolerated and disease-modifying new therapy for infantile spasms, including those refractory to ACTH.
Although AKT1 (v-akt murine thymoma viral oncogene homologue 1) kinase is a central member of possibly the most frequently activated proliferation and survival pathway in cancer, mutation of AKT1 has ...not been widely reported. Here we report the identification of a somatic mutation in human breast, colorectal and ovarian cancers that results in a glutamic acid to lysine substitution at amino acid 17 (E17K) in the lipid-binding pocket of AKT1. Lys 17 alters the electrostatic interactions of the pocket and forms new hydrogen bonds with a phosphoinositide ligand. This mutation activates AKT1 by means of pathological localization to the plasma membrane, stimulates downstream signalling, transforms cells and induces leukaemia in mice. This mechanism indicates a direct role of AKT1 in human cancer, and adds to the known genetic alterations that promote oncogenesis through the phosphatidylinositol-3-OH kinase/AKT pathway. Furthermore, the E17K substitution decreases the sensitivity to an allosteric kinase inhibitor, so this mutation may have important clinical utility for AKT drug development.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Summary
Objective
Infantile spasms (IS) have poor outcomes and limited treatment options, including vigabatrin, a γ‐aminobutyric acid (GABA) aminotransferase inactivator. Vigabatrin has been ...associated with retinal toxicity. A high affinity vigabatrin analogue (CPP‐115; Catalyst Pharmaceutical Partners, Inc., Coral Gables, FL, U.S.A.) has shown lower risk of retinal toxicity. Here, we test the efficacy of CPP‐115 in reducing spasms and its tolerability in the multiple‐hit rat model of IS, in which daily vigabatrin reduced spasms for only one day, but was not well tolerated.
Methods
Male rats were treated with the protocol of the multiple‐hit model of IS on postnatal day 3 (PN3). Using a randomized, blinded, vehicle‐controlled, dose‐response study design, CPP‐115 (0.1, 1, or 5 mg/kg intraperitoneally i.p.) or vehicle was given daily (PN4–12) or as a single injection (PN7) after spasm onset. Intermittent video‐ or video‐electroencephalography (EEG) monitoring was done. Secondary end points included the following: daily weights, survival, performance on open field activity, surface righting time, and negative geotaxis (PN3–20), horizontal bar (PN13–20), and Barnes maze (PN16–19). Statistics used a linear mixed model of raw or normalized log‐transformed data, taking into account the repeated observations on each animal.
Results
The lower CPP‐115 doses (0.1–1 mg/kg/day, PN4–12) reduced spasms between PN6 and 7 without increasing mortality. CPP‐115 at 5 mg/kg/day (PN4–12) reduced spasms earlier (PN5), but was eventually lethal. A single CPP‐115 injection (1 mg/kg, i.p.) decreased electroclinical spasms acutely but transiently. CPP‐115 transiently improved the probability to >50% reduction of spasms, but did not accelerate spasm cessation. CPP‐115 did not alter neurodevelopmental outcomes or visuospatial learning.
Significance
We provide proof‐of‐concept evidence that CPP‐115, a vigabatrin analogue, decreases spasms in the multiple‐hit rat model of IS at considerably lower and better tolerated doses than vigabatrin did in our previous studies. Further optimization of the treatment protocol is needed. CPP‐115 may be a promising new candidate treatment for IS with better tolerability than vigabatrin.
Objective
Infantile spasms may evolve into persistent epilepsies including Lennox‐Gastaut syndrome. We compared adult epilepsy outcomes in models of infantile spasms due to structural etiology ...(multiple‐hit model) or focal cortical inflammation and determined the anti‐epileptogenic effects of pulse‐rapamycin, previously shown to stop spasms in multiple‐hit rats.
Methods
Spasms were induced in 3‐day‐old male rats via right intracerebral doxorubicin/lipopolysaccharide (multiple‐hit model) infusions. Controls and sham rats were used. Separate multiple‐hit rats received pulse‐rapamycin or vehicle intraperitoneally between postnatal days 4 and 6. In adult mice, video‐EEG (electroencephalography) scoring for seizures and sleep and histology were done blinded to treatment.
Results
Motor‐type seizures developed in 66.7% of multiple‐hit rats, usually from sleep, but were reduced in the pulse‐rapamycin–treated group (20%, p = .043 vs multiple‐hit) and rare in other groups (0–9.1%, p < .05 vs multiple‐hit). Spike‐and‐wave bursts had a slower frequency in multiple‐hit rats (5.4–5.8Hz) than in the other groups (7.6–8.3Hz) (p < .05); pulse rapamycin had no effect on the hourly spike‐and‐wave burst rates in adulthood. Rapamycin, however, reduced the time spent in slow‐wave‐sleep (17.2%), which was increased in multiple‐hit rats (71.6%, p = .003). Sham rats spent more time in wakefulness (43.7%) compared to controls (30.6%, p = .043). Multiple‐hit rats, with or without rapamycin treatment, had right more than left corticohippocampal, basal ganglia lesions. There was no macroscopic pathology in the other groups.
Significance
Structural corticohippocampal/basal ganglia lesions increase the risk for post‐infantile spasms epilepsy, Lennox‐Gastaut syndrome features, and sleep dysregulation. Pulse rapamycin treatment for infantile spasms has anti‐epileptogenic effects, despite the structural lesions, and decreases the time spent in slow wave sleep.
Background: Diagnosis and reduction of syndesmosis injuries in ankle fractures can be challenging. Previous studies have demonstrated that standard radiographic measurements used to evaluate the ...integrity of the syndesmosis are inaccurate. The purpose of this study was to determine the adequacy of standard postoperative radiographic measurements in assessing syndesmotic reduction compared to CT and to determine the prevalence of postoperative syndesmotic malreduction in a patient cohort. Methods: Twenty-five patients with ankle fractures and syndesmotic instability who had open reduction and syndesmotic fixation were evaluated. All patients had a standard radiographic series postoperatively followed by a CT scan. Radiographic measurements were made by three observers to determine the tibiofibular relationship. Axial CT scan images were judged for quality of reduction of the syndesmosis by measuring the distance between the fibula and the anterior and posterior facets of the incisura. Differences between the anterior and posterior measurements of more than 2 mm were considered incongruous. Results: Six patients (24%) had evidence of postoperative diastasis using the radiographic criteria, four of whom had evidence of malreduction on postoperative CT scan. Conversely, 13 patients (52%) had incongruity of the fibula within the incisura on CT scan (average 3.6 mm, range 2.0 to 8.0 mm), only four of whom had one or more abnormal radiographic measurements. In 10 (77%) of the 13 malreductions seen on CT scan, the posterior measurement was greater, indicating that internal rotation or anterior translation of the fibula may have occurred. Sensitivity of radiographs was 31% and the specificity was 83% compared to CT. Conclusions: Many syndesmoses were malreduced on CT scan but went undetected by plain radiographs. Radiographic measurements did not accurately reflect the status of the distal tibiofibular joint in this series of ankle fractures. Furthermore, postreduction radiographic measurements were inaccurate for assessing the quality of the reduction. Although we did not seek to correlate functional outcomes, the known morbidity of postoperative syndesmotic malreduction should lead to heightened vigilance for assessing accurate syndesmosis reduction intraoperatively.
Syndesmotic injuries are common in ankle fractures. Traditional syndesmosis fixation may be associated with a secondary procedure. When the posterior malleolus is fractured, the posterior syndesmotic ...ligaments may remain intact and attached to the fragment. Our goals were to establish the incidence of syndesmotic ligament ruptures in pronation-external rotation type ankle injuries associated with posterior malleolar fractures, and to assess syndesmotic stability after fixation of the posterior malleolus compared with using a syndesmotic screw. Fifteen patients who sustained pronation-external rotation Stage 4 ankle fractures that involved the posterior malleolus were evaluated using radiographs and magnetic resonance imaging. No complete tears of the posterior-inferior tibiofibular ligament occurred. A pronation-external rotation fracture pattern with a posterior malleolar fragment was created in 10 lower extremity cadaver specimens with random fixation of the posterior malleolus or the syndesmosis. Compared with the intact specimens, stiffness was restored to 70% after fixation of the posterior malleolus, and to 40% after syndesmosis stabilization. Syndesmotic stability may be obtained more effectively by fixation of the posterior malleolus rather than by using a syndesmotic screw. Although additional clinical investigation is warranted, these concepts may be useful in eliminating syndesmotic screw fixation in select patients.
The incidence of seizures is particularly high in the early ages of life. The immaturity of inhibitory systems, such as GABA, during normal brain development and its further dysregulation under ...pathological conditions that predispose to seizures have been speculated to play a major role in facilitating seizures. Seizures can further impair or disrupt GABAA signaling by reshuffling the subunit composition of its receptors or causing aberrant reappearance of depolarizing or hyperpolarizing GABAA receptor currents. Such effects may not result in epileptogenesis as frequently as they do in adults. Given the central role of GABAA signaling in brain function and development, perturbation of its physiological role may interfere with neuronal morphology, differentiation, and connectivity, manifesting as cognitive or neurodevelopmental deficits. The current GABAergic antiepileptic drugs, while often effective for adults, are not always capable of stopping seizures and preventing their sequelae in neonates. Recent studies have explored the therapeutic potential of chloride cotransporter inhibitors, such as bumetanide, as adjunctive therapies of neonatal seizures. However, more needs to be known so as to develop therapies capable of stopping seizures while preserving the age- and sex-appropriate development of the brain.
The application of organic materials to soil can recycle nutrients and increase organic matter in agricultural lands. Digestate can be used as a nutrient source for crop production but it has also ...been shown to stimulate greenhouse gas (GHG) emissions from amended soils. While edaphic factors, such as soil texture and pH, have been shown to be strong determinants of soil GHG fluxes, the impact of the legacy of previous management practices is less well understood. Here we aim to investigate the impact of such legacy effects and to contrast them against soil properties to identify the key determinants of soil GHG fluxes following digestate application. Soil from an already established field experiment was used to set up a pot experiment, to evaluate N2O, CH4 and CO2 fluxes from cattle‐slurry‐digestate amended soils. The soil had been treated with farmyard manure, green manure or synthetic N‐fertilizer, 18 months before the pot experiment was set up. Following homogenization and a preincubation stage, digestate was added at a concentration of 250 kg total N/ha eq. Soil GHG fluxes were then sampled over a 64 day period. The digestate stimulated emissions of the three GHGs compared to controls. The legacy of previous soil management was found to be a key determinant of CO2 and N2O flux while edaphic variables did not have a significant effect across the range of variables included in this experiment. Conversely, edaphic variables, in particular texture, were the main determinant of CH4 flux from soil following digestate application. Results demonstrate that edaphic factors and current soil management regime alone are not effective predictors of soil GHG flux response following digestate application. Knowledge of the site management in terms of organic amendments is required to make robust predictions of the likely soil GHG flux response following digestate application to soil.
A pot experiment was set up to evaluate N2O, CH4 and CO2 fluxes from cattle‐slurry‐digestate–amended soils. Digestate stimulated emissions of the greenhouse gases (GHGs) compared to controls. The legacy of previous soil management was a key determinant of CO2 and N2O while edaphic variables, in particular texture, were the main determinant of CH4 flux from soil following digestate application. Results demonstrate that edaphic factors and current soil management regime alone are not effective predictors of soil GHG flux response following digestate application and knowledge of the site management is required to predict soil GHG flux response following digestate application to soil.
We used the BinaxNOW COVID-19 Ag Card to screen 1,540 asymptomatic college students for severe acute respiratory syndrome coronavirus 2 in a low-prevalence setting. Compared with reverse ...transcription PCR, BinaxNOW showed 20% overall sensitivity; among participants with culturable virus, sensitivity was 60%. BinaxNOW provides point-of-care screening but misses many infections.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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