FR Rates Research Articles

A novel nomogram to predict futile recanalization in patients with acute ischemic stroke undergoing mechanical thrombectomy.

Futile recanalization (FR) is defined as patients with acute ischemic stroke (AIS) due to large vessel occlusion who still exhibits functional dependence although undergoing successful mechanical thrombectomy (MT). We aimed to develop and validate a simple nomogram for predicting the probability of FR after MT treatment in AIS patients. Clinical data of AIS patients in the Jrecan clinical trial in China from March 2018 to June 2019 were collected as the derivation set (n = 162). Meanwhile, clinical data of AIS patients who underwent MT in Baotou Central Hospital and Ningbo No.2 Hospital from 2019 to 2021 were collected as the validation set (n = 170). Multivariate logistic regression analysis was performed for all variables that had p < 0.2 in the univariate analysis in the derivation set. The independent risk factors of FR were further screened out and a nomogram was constructed. The performance of the nomogram was analyzed in the derivation and validation set using C-index, calibration plots, and decision curves. No significant difference in FR rate was detected between the derivation set and the validation set [88/162 (54.32%) and 82/170 (48.23%), p = 0.267]. Multivariate logistic regression analysis showed that age ≥ 65 years old (OR = 2.096, 95%CI 1.024-4.289, p = 0.043), systolic blood pressure (SBP) ≥ 180 mmHg (OR = 5.624, 95%CI 1.141-27.717, p = 0.034), onset to recanalization time (OTR) ≥ 453 min (OR = 2.759, 95%CI 1.323-5.754, p = 0.007), 24 h intracerebral hemorrhage (ICH; OR = 4.029, 95%CI 1.844 ~ 8.803, p < 0.001) were independent risk factors for FR. The C-index of the nomogram of the derivation set and the verification set were 0.739 (95%CI 0.662~0.816) and 0.703 (95%CI 0.621~0.785), respectively. The nomogram composed of age, SBP, OTR, and 24 h ICH can effectively predict the probability of FR after MT in AIS patients.

Effect of replacement of fishmeal by soybean products with attractants supplementation on the growth performance, feed utilization, body composition, plasma physiological responses and hepatic antioxidant abilities of juvenile golden pompano Trachinotus ovatus

A feeding experiment was carried out to develop a practical diet with low fishmeal for juvenile golden pompano (Trachinotus ovatus) by substituting fishmeal protein with soybean products mixture. Six isocaloric (17.6 KJ g−1) diets were designed by replacing 0 (FM100), 5 (FM95), 10 (FM90), 15 (FM85), 20 (FM80), and 25% (FM75) of the fishmeal with soybean products mixture (SPM) (soybean meal and soybean protein concentrate). The experiment diets were supplemented with 1.5%, 3%, 4.5%, 6% and 7.5% squid paste as attractants or palatability enhancer. The experimental fish (6.9 g) were cultured in sea cages (1.0 m × 1.0 m × 1.5 m) with 25 fish in each cage. Fish were fed the corresponding experimental diets to satiation twice daily for 8 weeks. At the end of the feeding experiment, no differences were found in the final weight and weight gain (WG) of fish fed FM100, FM85, FM80, and FM75 diets (P &gt; 0.05). The WG was significantly (P &lt; 0.05) better in the fish-fed FM95 diet compared to FM100 and FM75 diets. FCR in diet FM95 and FM90 was significantly (P &lt; 0.05) than that of FM80 and FM75, but these values were not significantly different from those in other treatments. Although the condition factor value in diets FM90, FM85, and FM80 was significantly (P &lt; 0.05) higher than that of FM100, these values were not significantly different from the rest of the other groups. There was no statistical difference in SGR, FR, VSI, and survival rates among different dietary treatments. The plasma AST activity was significantly lower in fish fed FM90 diet compared to fish fed with control, FM85, FM80, and FM75 (P &lt; 0.05). There was no significant difference in plasma AST among all dietary treatments except FM95 and FM90. In contrast, the plasma AKP activity showed the opposite trend. Compared with the control, the fish-fed FM80 and FM75 diets had significantly decreased plasma cholesterol, triglyceride total protein, albumin, and globulin level (P &lt; 0.05) while significantly increasing plasma COR levels (P &lt; 0.05). There was no significant difference in ALT, Urea and glucose values among all treatments. No statistical difference was observed among the FM100, FM80, and FM75 treatments for those of plasma LYZ activity, C3, and C4 levels. The hepatic T-AOC and SOD activities were significantly increased in fish fed the FM90 diet (P &lt; 0.05) compared to those in fish fed with FM100 diet. According to the current experiment, it can be concluded that SPM supplemented with SP could partially substitute fishmeal (25%) for juvenile golden pompano without any adverse symptoms.

Spatial and temporal profile of high-frequency oscillations in posttraumatic epileptogenesis

We studied the role of temporal and spatial changes in high-frequency oscillation (HFO, 80–500 Hz) generation in epileptogenesis following traumatic brain injury (TBI).Experiments were conducted on adult male Sprague Dawley rats. For the TBI group, fluid percussion injury (FPI) on the left sensorimotor area was performed to induce posttraumatic epileptogenesis. For the sham control group, only the craniotomy was performed. After TBI, 8 bipolar micro-electrodes were implanted bilaterally in the prefrontal cortex, perilesional area and homotopic contralateral site, striatum, and hippocampus. Long-term video/local field potential (LFP) recordings were performed for up to 21 weeks to identify and characterize seizures and capture HFOs. The electrode tip locations and the volume of post TBI brain lesions were further estimated by ex-vivo MRI scans. HFOs were detected during slow-wave sleep and categorized as ripple (80–200 Hz) and fast ripple (FR, 250–500 Hz) events. HFO rates and the HFO peak frequencies were compared in the 8 recording locations and across 8-weeks following TBI.Data from 48 rats (8 sham controls and 40 TBI rats) were analyzed. Within the TBI group, 22 rats (55%) developed recurrent spontaneous seizures (E+ group), at an average of 62.2 (+17.1) days, while 18 rats (45%) did not (E- group). We observed that the HFOs in the E+ group had a higher mean peak frequency than the E- group and the sham group (P < 0.05). Furthermore, the FR rate of the E+ group showed a significant increase compared to the E-group (P < 0.01) and sham control group (P < 0.01), specifically in the perilesional area, homotopic contralateral site, bilateral hippocampus, and to a lesser degree bilateral striatum. When compared across time, the increased FR rate in the E+ group occurred immediately after the insult and remained stable across the duration of the experiment. In addition, lesion size was not statistically different in the E+ and E- group and was not correlated with HFO rates.Our results suggest that TBI results in the formation of a widespread epileptogenic network. FR rates serve as a biomarker of network formation and predict the future development of epilepsy, however FR are not a temporally specific biomarker of TBI sequelae responsible for epileptogenesis. These results suggest that in patients, future risk of post-TBI epilepsy can be predicted early using FR.

Meta‐analysis of post‐release fishing mortality in apex predatory pelagic sharks and white marlin

AbstractRobust assessments of the effects of fishing require accounting for components of fishing mortality, including post‐release fishing mortality (Fr). Random‐effects meta‐analysis synthesizedFrin seven pelagic shark species captured, tagged and released with 401 pop‐up satellite archival tags compiled from 33 studies and three gears (longline, purse‐seine, rod &amp; reel). The majority ofFroutcomes occurred within days of release, and the summary effect size forFrwas 0.27 [95%CI: 0.19–0.36], ranging from a low pooled effect size of 0.17 for blue shark (Prionace glauca,Carcharhinidae) to 0.38 (silky shark,Carcharhinus falciformis,Carcharhinidae).Frrates in blue shark were consistent over dissimilar spatial and temporal scales, and results from earlier meta‐analysis were replicated, which is the most powerful way to authenticate results. Condition at tagging was a strong predictor, and dichotomized survival outcomes in silky shark and no sex‐, size‐, location‐ or gear‐specificFrrates were demonstrated. Meta‐analyses and sensitivity analyses indicated exposure to risk factors and conditions whilst caught on the gear probably had the largest explanatory effect onFr, rather than stressors incurred during handling and release. Records from 549 tagged istiophorid billfishes (six species, three gears, 43 studies) demonstrated they are more robust to stressors sustained during capture, handling and release than pelagic sharks. Findings from previous meta‐analysis onFrrates in white marlin (Kajikia albida,Istiophoridae) were replicated. SynthesizedFrrates enable prioritizing approaches to mitigate by‐catch fishing mortality, to improve the quality of stock and ecological risk assessments and to expand our knowledge of factors influencing trophic structure.

Medetomidine–ketamine–sevoflurane anaesthesia in juvenile Nile crocodiles (Crocodylus niloticus) undergoing experimental surgery

ObjectiveTo describe the anaesthetic, physiological and side effects of intramuscular (IM) medetomidine and ketamine, followed by inhalational anaesthesia with sevoflurane, in Nile crocodiles (Crocodylus niloticus). Study designObservational trial. AnimalsTen juvenile captive-bred Nile crocodiles undergoing surgical implantation of skeletal beads and muscular electrodes. MethodsDuring preanaesthetic examination, the following variables were assessed: heart (HR) and respiratory (fR) rates, and response to palpebral, corneal and toe- and tail-pinch withdrawal reflexes. The crocodiles were injected IM with an initial combination of medetomidine and ketamine and re-evaluated at 5 minute intervals for 20 minutes, or until they appeared unresponsive. If that did not occur, the drugs were redosed according to a decision tree based on the observed effects. The righting, biting and palatal valve reflexes were assessed in the unresponsive crocodiles, and used to confirm anaesthetic induction. Anaesthesia was maintained with sevoflurane in oxygen. At the end of surgery, medetomidine was antagonized with IM atipamezole. ResultsThe decision tree identified 0.3 mg kg−1 medetomidine and 15 mg kg−1 ketamine as a useful drug combination, which resulted in anaesthetic induction and surgical anaesthesia 16 ± 8 and 16 (25–20) minutes after injection, respectively. Compared to baseline, HR and fR significantly decreased after anaesthetic induction (p < 0.001), but then remained stable throughout surgery. Intraoperatively, cloacal temperature [27 (26–30) °C] did not change over time (p = 0.48). The total dose of atipamezole was 2 (1–3) mg kg−1 and time to recovery was 36 (20–60) minutes. Perioperative complications were not observed. Conclusionsand clinical relevance Medetomidine and ketamine, injected IM and followed by sevoflurane anaesthesia, may be regarded as a useful anaesthetic technique for juvenile Nile crocodiles undergoing minimally invasive experimental surgery.

Post-release fishing mortality of blue (Prionace glauca) and silky shark (Carcharhinus falciformes) from a Palauan-based commercial longline fishery

Accounting for components of fishing mortality, including post-release mortality (Fr), is necessary for robust assessments of the effects of fishing. Forty-eight blue (Prionace glauca) and 35 silky sharks (Carcharhinus falciformes) were tagged with pop-up satellite archival tags to monitor Fr rates from pelagic longline vessels in the western tropical Pacific Ocean. There is a paucity of Fr studies at low latitudes and identifying factors that significantly explain Fr is critical for understanding fishing mortality. Mean Fr rates were 0.17 [95% CI 0.09–0.30] for blue shark and 0.20 [95% CI 0.10–0.36] for silky shark. When it occurred, Fr was acute with 87% of mortalities within 2 days of release. Several prognostic operational, environmental, biological and handling variables were evaluated to assess their influence on survival outcomes. Using Kaplan–Meier survival curves, logistic regression, accelerated failure time and Cox proportional hazards models to screen variables, the only significant prognostic or risk variable was health condition at haulback. There was close correspondence (~ 83% accuracy) between condition at capture and survival outcomes. Reliable methods to classify at-vessel condition represent an inexpensive and simple metric for estimating both Fr and at-vessel (Fc) mortality rates. Examining Fc rates in detail in longline fisheries using capture information on depth, temperature and dissolved oxygen that may act in synergy with condition code and hooking duration is a research priority. Results suggest that a large proportion of shark survive following release and that Fr rates can be increased by improving the haulback condition of captured sharks.

P291 Non-invasive detection of fast ripples in low-noise EEG recordings

Purpose Ripples (80–250 Hz) and fast ripples (FR, 250–500 Hz) are characterized by poor signal-to-noise ratio, which reduces their visibility in non-invasive recordings. While ripples are observed in scalp EEG, FR detection has been restricted to invasive recordings. We tested the detectability of FR in the scalp EEG of epilepsy patients, recorded with a low-noise amplifier, and quantified their specificity for the prospective epileptogenic zone (EZ). Method Scalp EEG was recorded during one hour of slow wave sleep in six patients with focal lateralized epilepsy. We used a custom-made low-noise 8-channel amplifier (noise level 2.3 nV/ √ Hz). Electrodes were placed symmetrically on both hemispheres, ipsilateral (EZ-h) as well as contralateral (nEZ-h) to the presumed epileptogenic area. Ripples and FR were detected by combining automated detection ( Burnos et al., 2016 ) and offline visual validation. Results For each patient, mean event rates were computed for EZ-h and nEZ-h. Across patients, FR rates were 0.17 ± 0.03 event/min in EZ-h and 0.11 ± 0.05 event/min in nEZ-h (p = 0.031). Ripple rates were 0.19 ± 0.34 event/min in EZ-h and 0.22/min ± 0.45 event/min in nEZ-h (n.s.). Across all channels, mean peak-to-peak amplitude FR was 1.02 ± 0.58 μ V on a background noise level of 0.33 ± 0.12 μ V while mean peak-to-peak ripple amplitude was 2.09 ± 1.15 μ V on a background noise level of 0.70 ± 0.37 μ V. Conclusion FR could be detected non-invasively on the scalp using an optimized low-noise amplifier. FR were more specific than ripples for the affected hemisphere. The opportunity to access FR non-invasively represents a substantial advance in scalp EEG recording and could contribute to therapy monitoring.

Prediction of seizure outcome improved by fast ripples detected in low-noise intraoperative corticogram.

Fast ripples (FR, 250-500Hz) in the intraoperative corticogram have recently been proposed as specific predictors of surgical outcome in epilepsy patients. However, online FR detection is restricted by their low signal-to-noise ratio. Here we propose the integration of low-noise EEG with unsupervised FR detection. Pre- and post-resection ECoG (N=9 patients) was simultaneously recorded by a commercial device (CD) and by a custom-made low-noise amplifier (LNA). FR were analyzed by an automated detector previously validated on visual markings in a different dataset. Across all recordings, in the FR band the background noise was lower in LNA than in CD (p<0.001). FR rates were higher in LNA than CD recordings (0.9±1.4 vs 0.4±0.9, p<0.001). Comparison between FR rates in post-resection ECoG and surgery outcome resulted in positive predictive value PPV=100% in CD and LNA, and negative predictive value NPV=38% in CD and NPV=50% for LNA. Prediction accuracy was 44% for CD and 67% for LNA. Prediction of seizure outcome was improved by the optimal integration of low-noise EEG and unsupervised FR detection. Accurate, automated and fast FR rating is essential for consideration of FR in the intraoperative setting.

Effect of Fertility Blend® Administration on the Oocytes Quality and Embryonic Development using assisted Reproductive Technology in Mice

Female Fertility Blend ® (FFB) is one of new nutritional supplement that used to enhance the fertility status in women. This supplement containing vitamins, minerals, enzymes, amino acids, all may improve the oocytes quality and ovarian function; at the same time protect oocytes from free radicals damage. The aim of the study is to examine the in vivo effect of FFB on oocyte quality, and in vitro fertilization rate (IVFR), and embryonic development (ED) at early cleavage stages using the mice as a model for human being. Therefore, two groups of mature female mice were involved (20 mouse each). The treated group is daily orally administrated by 3.4mg/kg /body weight from FFB for 10 days and the other groups (the control) were treated with FFB- free distilled water only for the same period. Oocytes were collected and an epididymal sperms from mature fertilized male mice are obtained and in vitro fertilization (IVF) is done. Following 24 and 48hrs from IVF, the FR and ED rate are recorded. This results showed a significant (P&lt;0.05) differences in fertilization rate and embryonic development when treating the female mice with FFB compared to control group. It is concluded that the FFB treatment has a great improvement in oocytes maturation and in vitro fertilization and embryonic development status.

Development of growth rate, body lipid, moisture, and energy models for white sturgeon (Acipenser transmontanus) fed at various feeding rates.

The objectives were to develop and evaluate: 1) growth rate models, 2) body lipid, moisture, and energy models for white sturgeon fed at various feeding rates (FR; % body weight [BW] per day) and then evaluate responses at proportions of optimum feeding rate (OFR) across increasing BW (g). For objective 1, 19 datasets from the literature containing initial BW, FR and specific growth rate (SGR; % BW increase per day) were used. For objective 2, 12 datasets from the literature (11 from objective 1) containing SGR, FR, final BW, body lipid (%), protein (%), ash (%), moisture (%), and energy (kJ/g) were used. The average rearing temperatures was 19.2 ± 1.5 °C (mean ± SD). The average nutrient compositions and gross energy of the diets were 45.7 ± 4.3% protein, 14.8 ± 3.2% lipid, and 20.4 ± 1.3 kJ/g, respectively. The logistic model was used for objectives 1 and 2 to develop a statistical relationship between SGR and FR, then an iterative technique was used to estimate OFR for each dataset. For objective 2, the statistical relationship between body lipid, energy, and moisture and FR was established. Using the OFR estimate, SGR, body lipid, energy and moisture were computed at various FR as a proportion of OFR. Finally, a nonparametric fitting procedure was used to establish relationships between SGR, body lipid, energy and moisture (responses) compared with BW (predictor) at various proportions of OFR. This allows visualization of the effect of under- or over-feeding on the various responses. When examining the differences between OFR at 100% and various proportions of OFR, SGR differences decrease and moisture differences increase as BW increases. Lipid and energy differences decrease as BW increases. To our knowledge, these are the first description of changes in nutrient compositions when white sturgeon are fed at various FR. Because physiological and behavioral properties that are unique to sturgeon, results from this study are specific to sturgeon under the conditions of this study and cannot be compared directly with salmonids even if some of the results are similar. This research provides insight to designing future nutritional studies in sturgeon.

Residual fast ripples in the intraoperative corticogram predict epilepsy surgery outcome

We studied whether residual high-frequency oscillations (80-500 Hz; ripples, 80-250 Hz), especially fast ripples (FRs, 250-500 Hz), in post-resection intraoperative electrocorticography (ECoG) predicted seizure recurrence in comparison to residual interictal spikes and ictiform spike patterns. We studied, retrospectively, ECoG recorded at 2,048 Hz after resection in a cohort of patients with refractory focal epilepsy. We analyzed occurrence and number of residual FRs, ripples, interictal spikes, and ictiform spike patterns within the last minute of each recording and compared these to seizure recurrence. We included 54 patients (median age 15.5 years) with 25 months median follow-up. Twenty-four patients had recurrent seizures. We found residual FRs, ripples, spikes, and ictiform spike patterns in 12, 51, 38, and 9 patients. Nine out of 12 patients with residual FRs had recurrent seizures (p = 0.016, positive predictive value 75%). Other ECoG events did not predict seizure recurrence. Patients with seizures had higher FR rates than seizure-free patients (p = 0.022). FRs near the resection and in distant pathologic areas could have changed the resection in 8 patients without harming functionally eloquent areas. One seizure-free patient had FRs in distant functionally eloquent areas. Residual FRs in post-resection ECoG are prognostic markers for seizure recurrence, especially if their number is high. Tailoring could rely on FRs, but requires careful assessment of the ECoG, as FRs in functionally eloquent areas might not be pathologic.

Computational study of solid circulation in chemical-looping combustion reactor model

A three-dimensional computational fluid dynamic (CFD) model has been developed for simulating full-loop solid circulation in a dual circulating fluidized bed (DCFB) chemical loop combustion (CLC) reactor model. The standard k-ε turbulence model and kinetic theory of granular theory based Eulerian multiphase model were used to describe the gas and solid motions, respectively. The simulations focused on the investigation of solid circulation in a CLC reactor model which consists of an air reactor (AR, height of 1.36m, diameter of 0.05m) and a fuel reactor (FR, height of 0.97m, diameter of 0.054m). Key gas–solid flow behaviors related to gas–solid circulation behaviors, e.g. the transient flow regime, solid velocity, solid distribution and circulation characteristics, were numerically investigated. It was found that a core–annulus flow structure appeared in FR. The influences of FR and LLS fluidization flow rate on global and internal circulation rate were studied separately. With FR fluidization flow rate increasing, the time-averaged axial solid volume fraction in the top region of FR first increased and then decreased. The influences of FR and LLS fluidization rate on circulation dynamic characteristics, including circulation fluctuation strength and circulation stability, were also numerically investigated in this work.

Abstract W MP10: Outcome and Futile Recanalization in Basilar Artery Occlusion - Systematic Analysis

Background: Basilar artery occlusion (BAO) is a most devastating form of stroke, and the current wisdom is to reverse it with revascularization therapies. Pharmacological thrombolysis have been adjuncted or replaced with endovascular thrombectomy devices. The preferred approach remains unknown and most recanalizations are futile with no clinical benefit. Methods: To determine whether invasive, endovascular interventions are superior to pharmacological thrombolysis alone we analyzed systematically the reported outcomes produced by variable BAO recanalization protocols. Information was retrieved from 15 reports published from 2005 comprising 803 patients in 17 cohorts. In the largest single-center cohort (162, Helsinki), predictors of futile recanalization (FR;3-month modified Rankin Scale [mRS] score 4 to 6) were determined. Results: Good outcome was reported by pharmacological protocols less frequently than by mechanical approaches either alone or on-demand (24.4% vs. 35.5% %, p&lt;0.001), accompanied by lower recanalization rates (70.9% vs. 84.1%, p&lt;0.001)(Figure). Afforded by superior recanalization rate at 91%, good outcome was reached by primary thrombectomy with stent-retrievers in 36%, but at the cost of substantial FR rate at 60%. In the largest single-center cohort, the single most significant predictor was extensive baseline ischemia, increasing the odds of futility 20-fold (95%CI 4.39-92.29, p&lt;0.001). Other attributes of futility were ventilation support and history of atrial fibrillation or previous stroke. Conclusion: Mechanical endovascular approaches have reported superior primary outcome rates over pharmacological thrombolysis in BAO. Stricter patient selection, most notably to exclude victims of already extended ischemia, would assist in translating excellent recanalization rates into improved clinical outcomes and more acceptable futility rates.

A comparison of low dose tiletamine-zolazepam or acepromazine combined with methadone for pre-anaesthetic medication in cats

ObjectiveTo compare the level of sedation, cardiorespiratory changes, and quality of recovery in cats receiving methadone plus either low dose tiletamine-zolazepam or acepromazine for premedication prior to general anaesthesia for neutering. Study designProspective, randomized, blinded clinical study. AnimalsTwenty cats 0.54 ± 0.12 years-old (mean ± SD), weighing 3.17 ± 0.65 kg (10 male and 10 female). MethodsCats were allocated randomly to receive intramuscularly either 0.03 mg kg−1 acepromazine (ACE) or 3 mg kg−1 tiletamine-zolazepam (TZ), both regimens combined with 0.2 mg kg−1 methadone for premedication. Sedation was assessed 25 minutes after premedication using a visual analogue scale (VAS) and a simple descriptive scale (SDS). Anaesthesia was induced with alfaxalone and maintained with isoflurane. Physiological parameters were recorded at 1, 3 and 5 minutes post-endotracheal intubation. Recovery from cessation of isoflurane was timed and quality assessed using a SDS and a VAS. Data was analysed with Mann–Whitney U-test, students t-test, anova or ordinal logistic regression as relevant. Significance was taken as p < 0.05. ResultsSedation was more pronounced in TZ than ACE as indicated by higher VAS (67 ± 21 versus 13 ± 5) and SDS scores [4 (1–4) versus 1 (0–1)]. Following sedation, Heart (HR) and respiratory (fR) rates did not differ between groups. After anaesthetic induction, at times 1, 3 and 5 HR, systolic arterial pressure and end tidal carbon dioxide were significantly higher and fR was significantly lower in TZ than ACE. Recovery quality was similar between groups. In both groups, times to extubation, head lift and sternal recumbency were similar, but time (minutes) until standing was significantly longer in TZ (31 ± 16) than ACE (18 ± 11). Conclusion and clinical relevanceLow dose tiletamine-zolazepam combined with methadone provided superior sedation to ACE. Recovery quality was similar, although time to standing was longer.

IL‐1β microinjections into the nucleus tractus solitarius in rodents alter cardiorespiratory patterning consistent with endotoxemia (686.19)

Endotoxemia increases heart (HR) and respiratory (fR) rates and disrupts cardio‐respiratory coupling (CRC). We previously identified expression of proinflammatory cytokines in the nTS during endotoxemia which was associated with increases in HR and fR, as well as uncoupling of cardio‐respiratory patterns. We hypothesized that microinjection of the proinflammatory cytokine IL‐1β into the nTS would increase HR, fR, and alter cardio‐ventilatory coupling (CVC), defined as the significant tendency for a heartbeat to occur at a preferred latency prior to the next breath. To test this hypothesis, we injected IL‐1β (0.5 ng, n=8) bilaterally into the nTS of anesthetized (isoflurane) spontaneously breathing adult male Harlan Sprague‐Dawley rats (n=12) and recorded diaphragmatic electromyogram (EMG) and electrocardiogram (ECG). 2h after focal injections of IL‐1β, fR increased 32% (from 42.9 ± 2.2 to 57.0±15 brths/min; p&lt;0.05). CVC was analyzed with custom software and χ2 from multi‐ordered histograms was calculated. 2h post IL1‐β injection, the average χ2 value reduced from 40.76 ± 5.9 to 15.91 ± 3.6 (p&lt;0.001) indicating loss of CVC. We conclude that exogenous IL‐1β injections into the nTS (reduced model of brainstem inflammation) reproduces some of the cardiorespiratory changes observed in experimental endotoxemia, and may contribute to altered cardio‐respiratory coupling.Grant Funding Source: T32 HL007913, NS069220, VA I01BX000873

Effect of medetomidine-butorphanol and dexmedetomidine-butorphanol combinations on intraocular pressure in healthy dogs

ObjectiveTo assess the effects of intravenous (IV) medetomidine-butorphanol and IV dexmedetomidine-butorphanol on intraocular pressure (IOP). Study designProspective, randomized, blinded clinical study. AnimalsForty healthy dogs. Mean ± SD body mass 37.6 ± 6.6 kg and age 1.9 ± 1.3 years. MethodsDogs were allocated randomly to receive an IV combination of dexmedetomidine, 0.3 mg m−2, combined with butorphanol, 6 mg m−2, (group DEX) or medetomidine 0.3 mg m−2, combined with butorphanol 6 mg m−2, (group MED). IOP and pulse (PR) and respiratory (fR) rates were measured prior to (baseline) and at 10 (T10), 20 (T20), 30 (T30) and 40 (T40) minutes after drug administration. Oxygen saturation of hemoglobin (SpO2) was monitored following sedation. Data were analyzed by anova followed by Dunnett's tests for multiple comparisons. Changes were considered significant when p < 0.05. ResultsFollowing drug administration, PR and fR were decreased significantly at all time points but did not differ significantly between groups. Baseline IOP in mmHg was 14 ± 2 for DEX and 13 ± 2 for MED. With both treatments, at T10, IOP increased significantly (p < 0.001), reaching 20 ± 3 and 17 ± 2 for DEX and MED respectively. This value for DEX was significantly higher than for MED. There were no significant differences in IOP values between groups at any other time points. At T30 and T40, IOP in both groups was below baseline (DEX, 12 ± 2 and 11 ± 2: MED 12 ± 2 and 11 ± 2) and this was statistically significant, for DEX. Conclusions and clinical relevanceAt the documented doses, both sedative combinations induced a transient increase and subsequent decrease of IOP relative to baseline, which must be taken into consideration when planning sedation of animals in which marked changes in IOP would be undesirable.

Comparison of mean heart rate in anaesthetized dachshunds and other breeds of dog undergoing spinal Magnetic Resonance Imaging

ObjectiveClinical experience suggests that dachshunds are prone to bradycardia during general anaesthesia (GA). The study investigated mean heart rates in anaesthetized dachshunds and other breeds of dog. Study DesignRetrospective clinical study. AnimalsSixty one dachshunds and 62 dogs of other breeds met inclusion criteria. MethodsClinical records of small breed dogs undergoing GA for spinal Magnetic Resonance Imaging between September 2008 and March 2010 were identified and examined. Data collected included drugs administered, baseline heart (HR) and respiratory (fR) rates and rectal temperature. The following information was noted from anaesthetic records: HR, fR, mean non-invasive arterial pressure and end-tidal carbon dioxide (Pe′CO2) and anaesthetic agent (Fe′agent) during the first 60 minutes of anaesthesia; rectal temperature at a time closest to the cessation of anaesthesia, ventilatory mode (spontaneous/mechanical) and fluid infusion rate. Univariate analysis with Student t-test and Fisher's test identified parameters significant in predicting a lowered HR. A multivariate analysis investigated their effect on the mean HR during GA. ResultsNo differences were found between groups regarding: age, baseline HR, baseline temperature, incidence of hypotension, Fe′agent, mean Pe′CO2 and fluid infusion rate. Body mass was smaller for dachshunds (6.7 ± 1.5 kg) compared to other breeds (7.8 ± 1.8 kg) (p = 0.0005). The lowest HR recorded was lower in dachshunds (64 ± 19 beats minute−1) compared to other breeds (72 ± 21 beats minute−1) (p = 0.03). Mean HR was lower in dachshunds (75 ± 21 beats minute−1) compared to other breeds (84 ± 21 beats minute−1) (p = 0.02). Post-procedural temperature (°C) was lower in dachshunds (35.5 ± 1.1) compared to other breeds (36.1 ± 1.2) (p = 0.007) and anticholinergics were also administered more frequently (p = 0.026). Multivariate analysis identified that breed and mean Pe′CO2 affected mean HR during anaesthesia. ConclusionThis study supported our hypothesis that dachshunds have a lower mean HR under GA than other small breed dogs.

The effect of the relaxation oscillation frequency of chaotic semiconductor laser on the rate of random sequence

In this paper, chaotic light generated by semiconductor laser with optical feedback is employed as physical entropy source to generate high-speed random sequence. The relationship between autocorrelation coefficient of chaotic signal and run number of random sequence is analyzed. Based on the analysis, the changes of random sequence run number are further investigated at different ratios between laser relaxation oscillation frequency fr and random sequence generation rate fn. The results show that random sequence run can easily meet the requirement for run test of NIST SP800-22 when the ratio between fr and fn satisfies the equation of fr/fn=(2k+1)/4. When k in the equation is equal to 1, the maximal rate fn=4fr/3 of random sequence is obtained.

Comparison of lidocaine, lidocaine/epinephrine or bupivacaine for thoracolumbar paravertebral anaesthesia in fat-tailed sheep

ObjectiveTo evaluate the speed of onset and duration of loss of sensation in the flank following paravertebral administration of lidocaine (with or without epinephrine) or bupivacaine. Study designBlinded, randomized experimental study. AnimalsNine healthy fat-tailed male lambs (mean weight ± SD, 22.9 ± 3 kg). Each animal was used twice. MethodsAnimals were allocated randomly to receive two of three treatments: lidocaine 2% (LID, n = 6), lidocaine with epinephrine 5 μg mL−1 (LIDEP, n = 6) or bupivacaine 0.5% (BUP, n = 6). The sheep received a total volume of 9 mL (3 mL for each paravertebral nerve) of anaesthetic. Onset and duration of loss of sensation on the flank were evaluated using nociceptive stimuli (superficial and deep pin-prick and clamping with a haemostat). Values for heart (HR) and respiratory (fR) rates, rectal and skin temperatures were recorded before and at predetermined intervals after paravertebral injection. Parameters were compared using anova followed by Duncan’s test where relevant. ResultsMean ± SD times to onset of loss of flank sensation following paravertebral administration of LID, LIDEP or BUP were 1.8 ± 1.2, 2.0 ± 0.9 and 3.6 ± 1.3 minutes, respectively. Durations of action in minutes were 65 ± 18, 95 ± 46 and 303 ± 98, respectively. Onset and duration of effects after BUP treatment were significantly longer than after LID or LIDEP (p < 0.05), but did not differ significantly between LID and LIDEP. No clinical signs of local anaesthetic toxicity were noticed and HR and fR remained stable with all protocols. Conclusions and clinical relevanceParavertebral administration of bupivacaine produces a longer duration of anaesthesia when compared to lidocaine with or without epinephrine and is indicated when prolonged flank surgery is to be performed.

High frequency oscillations and seizure frequency in patients with focal epilepsy

High frequency oscillations (HFOs) have been associated with epileptogenicity. In rats, the extent of HFOs (>200 Hz) is correlated with seizure frequency. We studied whether the same applies to patients with focal epilepsy. Thirty-nine patients with intracerebral EEG sampled at 2000 Hz were studied for interictal ripples (80-250 Hz), fast ripples (FR, 250-500 Hz) and spikes. Seizure frequency before implantation was compared to numbers of channels with HFOs (>1/min). Analyses were repeated for HFO rates of >5, >10 and >20. Separate analyses were done for 25 patients with temporal lobe epilepsy only and for a selection of similar unilateral temporal channels in 12 patients. No linear correlation or trend was found relating the number of channels with HFOs and seizure frequency. There was a linear positive correlation between the number of channels with more than 20 FRs/min and seizure frequency. The hypothesis that the more tissue generating HFOs, the higher the seizure frequency, was not confirmed, though there might be a correlation for high FR rates.