Electrical stimulation of peripheral nerve fibers and dorsal column fibers is used to treat acute and chronic pain. Recent studies have shown that sensitized A-fibers maybe involved in the relay of ...pain information. These nerve fibers also carry sensory-induced action potentials (APs), such as proprioception, mechanoreception, etc. Electrical stimulation of these nerve fibers can result in interactions between sensoryinduced APs and stimulation-induced APs. For example, the sensory-induced APs can collide with stimulus APs, and thus may never be relayed to the brain. In this study, we aimed to quantify the effects of stimulation frequency on these interactions. Specifically, we focused on the goal of stimulation to simultaneously (i) block noxious sensory signals while (ii) relaying innocuous sensory signals from the periphery to the brain via a myelinated nerve fiber. We defined a performance metric called the "selective relay (SR)" measure. Specifically, we constructed a tractable model of a nerve fiber that receives two inputs: the underlying sensory activity at the bottom of the fiber (noxious or innocuous), and the external stimulus applied to the middle of the fiber. We then defined relay reliability, R, as the percentage of sensory APs that make it to the top of the fiber. SR is then a product of relaying innocuous sensory information while blocking noxious pain stimuli, i.e., SR = R sen (1-R pain ). We applied the two inputs to the fiber at various frequencies and analyzed relay reliability and then we studied selective relay assuming noxious and innocuous stimuli produce APs with distinct frequencies. We found that frequency stimulation between 50-100 Hz effectively blocks relay of low-frequency pain signals, allowing mid-to-high frequency sensory signals to transmit to the brain.
To compare high K(+ )-induced contraction and optimal resting tension measured by two commonly used techniques of hypertonic and isotonic K(+ ) in aortas with and without adventitial fat from various ...age rats.
Three age groups of rats (15, 25, and 62 weeks) were used to prepare thoracic aortic rings in which adventitial fat was either removed or left intact. High K(+ ) (30 mmol/L)-induced contractions were observed under increasing resting tensions of 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 g. Optimal resting tension was the resting tension at which the aorta showed a maximal contraction.
The contractions induced by 2 kinds of high K(+ ) were significantly different. Hypertonic and isotonic K(+ ) induced a different style of contraction, and the pattern varied with different ages. At the age of 15 weeks, isotonic K(+ )-induced contractions were greater than hypertonic K+-induced contractions. However, at the age of 62 weeks, isotonic K(+ )-induced contractions were smaller than hypertonic K(+ )-induced contractions. Optimal resting tensions measured by 2 kinds of high K(+ ) were inconsistent. Optimal resting tensions in different kinds of aortic preparations from various age rats were almost a constant of 2 g, determined by isotonic K(+ ), but a variable, determined by hypertonic K(+ ). The adventitial fat could delay the development of high K(+ )-induced contractions at different resting tensions, but had little effect on the maximal contractions.
Hypertonic and isotonic K(+ ) may produce different contractions resulting in differences in optimal resting tension in rat aorta.
Objective: Multiple lines of evidence suggest that general anesthesia helps the recovery from sleep deprivation. However, little is known about the underlying neurochemical mechanisms. In the current ...study, we investigated the effect of anesthetic propofol on the release of glutamate (Glu) and γ-amino butyric acid (GABA) in the hippocampal CA1 region of rat with 24 h-paradoxical sleep deprivation (PSD).
Methods: A guide cannula for microdialysis was inserted into the CA1 region of hippocampus in rats. At six days after cannula implantation, rats received 24 h-PSD by using the platform-water tank method. The rats were then subjected to natural sleep or propofol anesthesia (100 mg/kg, i.p.), respectively, after 24-h PSD. Microdialysis samples from hippocampus were collected before and at the end of PSD, and also at 1, 3, 6, and 8 h post-PSD. The concentrations of Glu and GABA in collected samples were determined by using high performance liquid chromatography.
Results: The current study showed that 24 h-PSD significantly increased the release of Glu and GABA in the hippocampus in rats. In both natural sleep and propofol anesthesia groups, the upregulated Glu and GABA levels after PSD gradually decreased and returned to the baseline level by 8 h post-PSD.
Conclusion: Our data indicate that propofol anesthesia promotes the restoration of disturbed excitatory and inhibitory neurotransmitter release in the hippocampus after PSD, similar to the beneficial effects of natural sleep. This finding suggests that propofol anesthesia may be a viable pharmacotherapeutic strategy for the treatment of certain sleep disorders that share similar mechanisms with PSD.
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Background: Treatment for recurrent brain metastasis remains uncertain. The purpose of this research was to evaluate the efficacy and toxicity of FSRS with adjuvant bevacizumab ...as a new salvage treatment for locally recurrent brain metastases with high dose irradiation previously. Methods: Patients with locally recurrent intracranial metastasis with irradiation previously were enrolled in this prospective study. Salvage FSRS dose ranged from 9.5 to 29 Gy in two to five sessions with 62–75% isodose line. Adjuvant bevacizumab was prescribed four cycles (5 mg/kg, q3w). Magnetic resonance imaging (MRI), Karnofsky Performance Scale (KPS), adverse events and clinical outcomes were recorded. The primary objective of this study was to identify the overall survival after salvage treatment. Secondary objectives included clinical response (KPS), imaging response (MRI) and adverse events. Results: From December 2009 to October 2016, 24 patients were enrolled. Of these patients, 9 received WBRT followed by SRS, and 15 underwent SRS. The median 1-year overall survival (OS) after salvage SRS was 87.5%. No treatment-related grade 4 adverse events were recorded. Grade 1/2 fatigue was observed in 8 (33%) patients followed by headache, hypertension and nausea. Grade 3 fatigue and headache occurred in 1 patient. No grade 4 toxicity was observed. Conclusions: Salvage FSRS with early use of low dose adjuvant bevacizumab treatment showed favourable clinical and radiologic control with manageable toxicity for locally recurrent brain metastasis patients who underwent high dose irradiation previously. The diagnosis of RN and LR after salvage FSRS merit further study. Table: see textTable: see textTable: see text
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Background: ‘Watch and Wait’ policy has currently led to growing interest for organ-preservation after neoadjuvant chemoradiation (nCRT) to improve quality of life. However, how to ...predict and select patients who may achieve clinical complete response is still an unsolved issue. We conducted a pilot study to evaluate the potential role of ctDNA as a biomarker to predict treatment outcome and improve risk stratification in locally advanced rectal cancer (LARC). Methods: In this study, we recruited 119 patients with LARC receiving nCRT. 595 serial plasma samples were collected at d0, d15, d25 of radiotherapy as well before and 7 days post surgery. The level of ctDNA was calculated by dynamic monitoring the mutant allele frequency of somatic mutations in plasma. Plasma and tissue samples were subjected to targeted-NGS using a 422 cancer-related genes panel. We followed up patients with concomitant CT until disease progression or death. Results: Detected mutation of TP53 and APC gene in pre-treatment samples was negatively correlated with patients’ response to nCRT. Alterations in homologous recombination and adherens junction pathways were associated with a better response (P < 0.05). Detection of pre-treatment mutations in any time points during nCRT was significantly (P = 0.03) decreased from TRG3 to TRG0 group (33%, 29%, 22% and 4%, respectively); while detection of acquired mutations showed an opposite trend (P = 0.04). A predictive model based on support vector machine was developed for prediction of pCR achieving a mean AUC of 0.85 assessed by repeated cross validation. Further, detection of pre-treatment mutations after completion of nCRT was significantly associated with worse disease-free survival (DFS) (P < 0.05). Through tracking clonal extinction, persistence and emergence, patients were grouped into four evolutionary subtypes with distinct TRG and DFS. Conclusions: Our data showed the prognostic value of ctDNA on DFS. Dynamic monitoring of ctDNA can be used to predict TRG and prognosis in LARC patients receiving nCRT. ctDNA sequencing depicts the evolutionary trajectories of sensitive and resistant clones during nCRT in LARC. CtDNA could potentially be used to guide patient selection for W&W strategy.
Effects of SRT and carbon concentration on the PHB of the anaerobic/aerobic SBR process are studied. The results show that by the order of SBR51,SBR10 and SBR52,the maximum PHB content of MLVSS were ...9.8%, 5.72% and 18.89%, respectively, while carbon translating ratios were 46%, 34% and 36.3% during the first 20min of aerobic phase and PHB forming rate were 196.6mg/(L x h), 140mg/(L x h) and 295.35mg/(L x h). PHB degradation rate can be described with a first order degradation rate with respect to the PHB content of the cells. Reclamation of PHB should consider from several factors. Carbon concentration gradient is the main factor influencing PHB formation under batch experiment.
Highlights • MrgC is expressed in both IB4+ and CGRP+ DRG neurons in mice and rats. • An L5 spinal nerve injury decreased MrgC expression in injured L5 DRG. • However, L5 nerve injury increased MrgC ...expression in adjacent uninjured L4 DRG. • Mrg KO mice exhibited prolonged mechanical hypersensitivity after nerve injury.
In order to understand growth of plant and its effect on ecological restoration of riparian zone, pilot-scale Scirpus yagara Ohw riparian zone had been studied for one year. Height and density of ...Scirpus yagara Ohw in different water depth showed that the water depth endurance of Scirpus yagara Ohw was not strong, and it growed and germinated better in shallow water. Contrast between harvest area and without harvest area showed that harvest was good for germination and growth of Scirpus yagara Ohw in next year. Distribution of biomass and N and P fixation between the underground and overground Scirpus yagara Ohw showed that N and P fixation of the underground was 50% and 126% more than that of the overground, respectively. Harvest of the overground Scirpus yagara Ohw can remove 40.5% of the total N and 30.6% of the total P. Dunked in water for 130 days, the overground Scirpus yagara Ohw lose 27.10% of its dry weight, 40.80% of the total N and 76.80% of tha total P. And the released pollutants have no serious
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