Phase-change material cooling blanket: A feasible cooling choice during transport after exercise-induced hyperthermia.

BACKGROUND: Exercise-induced hyperthermia preceding the onset of exertional heatstroke requires a rapid reduction in the body core temperature (Tcore) to ensure safety. In recent years, phase-change material (PCM) cooling devices have been increasingly used for rapid cooling after hyperthermia due to their superior capacity for heat absorption. OBJECTIVES: This study aimed to evaluate the cooling performance and effectiveness of a PCM cooling blanket on heart rate (HR) and heart rate variability (HRV) recovery after exercise-induced hyperthermia. DESIGN: Randomized cross-over. METHODS: The study participants were 12 male volunteers who were engaged in professional training and completed an endurance exercise for approximately 30 min in a hot and humid environment (temperature ≈ 30 °C; relative humidity ≈ 66%). The participants underwent a 30-min cooling trial after exercise, receiving either treatment with a PCM cooling blanket (PCM group) or natural cooling (CON group). The Tcore, HR, and HRV time-domain indices were used for analysis. RESULTS: The Tcore values were significantly lower in the PCM group during cooling. Reductions in the Tcore from precooling to 20 min of cooling were significantly greater in the PCM group than in the CON group. The HR in the PCM group was lower than that recorded in the CON group at 10 and 20 min of cooling. The reduction in HR during cooling from precooling was also significantly greater in the PCM group. HRV time-domain indices during cooling in the PCM group were significantly lower compared with the CON group while elevations in some HRV time-domain indices from precooling to postcooling were significantly greater in the PCM group than in the CON group. CONCLUSIONS: The PCM cooling blanket had good cooling performance and the ability to hasten recovery of both HR and HRV. It may serve as a feasible cooling choice during transport after exercise-induced hyperthermia.

The impact of perceived emotions on toddlers' word learning.

Others' emotional expressions affect individuals' attention allocation in social interactions, which are integral to the process of word learning. However, the impact of perceived emotions on word learning is not well understood. Two eye-tracking experiments investigated 78 British toddlers' (37 girls) of 29- to 31-month-old retention of novel label-object and emotion-object associations after hearing labels presented in neutral, positive, and negative affect in a referent selection task. Overall, toddlers learned novel label-object associations regardless of the affect associated with objects but showed an attentional bias toward negative objects especially when emotional cues were presented (d = 0.95), suggesting that identifying the referent to a label is a competitive process between retrieval of the learned label-object association and the emotional valence of distractors.

The prevalence and characterization of Bacillus cereus isolated from raw and pasteurized buffalo milk in southwestern China.

Bacillus cereus is an important food-borne pathogenic bacteria and a putrid microorganism in the dairy industry. Raw and pasteurized buffalo milk play important roles in the dairy market in southwestern China. However, the reports on the prevalence and characterization of B. cereus strains isolated from the above sources are lacking. In this study, 150 raw buffalo milk samples and 300 pasteurized buffalo milk samples were collected from 3 provinces in southwestern China. The genotype, virulence gene distribution, antibiotic resistance, and biofilm-forming ability of isolates were analyzed. Ninety-six B. cereus strains were isolated and identified: 50 isolates (33.3%) from buffalo raw milk and 46 isolates (15.3%) from pasteurized buffalo milk. These strains were classified into 41 sequence types (ST) and 5 groups, of which ST857 was the predominant ST. The detection rates of virulence genes nheABC cluster, hblACD cluster, cytK, bceT, entFM, hlyII, and cesB were 89.6%, 13.5%, 64.6%, 71.9%, 84.4%, 62.5%, and 6.25%, respectively. The antimicrobial susceptibility testing showed that more than 90% of the isolates were susceptible to gentamicin, chloramphenicol, ciprofloxacin, erythromycin, vancomycin, and tetracycline, as well as resistant to ampicillin, cefepime, oxacillin, and rifampin. The results of biomass biofilm evaluation of the isolates on the stainless-steel tube showed that the optical density values at a wavelength of 595 nm of all strains in group I were greater than 1, with the strongest overall biofilm-forming ability among 5 groups, and the overall biofilm-forming ability of group III was the weakest. There was a relationship between the biofilm-forming ability and phylogenetic relationship of B. cereus strains. Taken together, our findings are the first to report the contamination situation and characterization of B. cereus isolated from raw and pasteurized buffalo milk in southwestern China as well as indicate the potential risk posed by this pathogen to dairy industry and public health.

Genome-wide expanding of genetic evolution and potential pathogenicity in Vibrio alginolyticus.

Vibrio alginolyticus, an emergent species of Vibrio genus, exists in aquatic and marine environments. It has undergone genetic diversification, but its detailed genomic diversity is still unclear. Here, we performed a multi-dimensional comparative genomic analysis to explore the population phylogeny, virulence-related genes and potential drug resistance genes of 184 V. alginolyticus isolates. Although genetic diversity is complex, we analysed the population structure using three sub-datasets, including the subdivision for three lineages into sublineages and the distribution of strains in the marine ecological niche. Accessory genes, most of which reclassified V. alginolyticus genomes as different but with relatively close affinities, were nonuniformly distributed among these isolates. We demonstrated that the spread of some post-evolutionary isolates (mainly L3 strains isolated from Chinese territorial seas) was likely to be closely related to human activities, whereas other more ancestral strains (strains in the L1 and L2) tended to be locally endemic and formed clonal complex groups. In terms of pathogenicity, the potential virulence factors were mainly associated with toxin, adherence, motility, chemotaxis, and the type III secretion system (T3SS). We also found five types of antibacterial drug resistance genes. The prevalence of ß-lactam resistance genes was 100%, which indicated that there may be a potential risk of natural resistance to ß-lactam drugs. Our study reveals insights into genomic characteristics, evolution and potential virulence-associated gene profiles of V. alginolyticus.

Expression of the type VI secretion system 1 component Hcp1 is indirectly repressed by OpaR in Vibrio parahaemolyticus.

The type VI secretion system (T6SS) is bacterial protein injection machinery with roles in virulence, symbiosis, interbacterial interaction, antipathogenesis, and environmental stress responses. There are two T6SS loci, T6SS1 and T6SS2, in the two chromosomes of Vibrio parahaemolyticus, respectively. This work disclosed that the master quorum sensing (QS) regulator OpaR repressed the transcription of hcp1 encoding the structural component Hcp1 of T6SS1 in V. parahaemolyticus, indicating that QS had a negative regulatory action on T6SS1. A single σ(54)-dependent promoter was transcribed for hcp1 in V. parahaemolyticus, and its activity was repressed by the OpaR regulator. Since the OpaR protein could not bind to the upstream region of hcp1, OpaR would repress the transcription of hcp1 in an indirect manner.

[An experimental study on the effects of rhythmic abdominal lifting and compression during cardiopulmonary resuscitation in a swine model of asphyxia].

OBJECTIVE: To compare the hemodynamic and respiratory influences of chest compression- cardiopulmonary resuscitation (CC-CPR) and rhythmic abdominal lifting and compression-cardiopulmonary resuscitation (ALC-CPR) in a swine model of asphyxia cardiac arrest (CA), and evaluate the effectiveness of rhythmic abdominal lifting and compression. METHODS: Thirty swines were randomly divided into two groups, with 15 swines in each group. CA model was reproduced by asphyxia as a result of clamping the trachea, and CC-CPR and ALC-CPR was conducted in two groups, respectively. Electrocardiogram (ECG), pulse oxygen saturation [SpO(2)], end-tidal partial pressure of carbon dioxide [P(ET)CO(2)], aorta systolic blood pressure (SBP), diastolic blood pressure (DBP), central venous pressure (CVP), and tidal volume (VT) were monitored continuously from 10 minutes before asphyxia to the end of experiment. The aorta mean arterial pressure (MAP), coronary perfusion pressure (CPP) and minute ventilation (MV) were calculated. Artery blood samples were collected to determine the blood gas analysis at 10 minutes before asphyxia, 10 minutes after asphyxia, and 5, 10, 20 minutes after resuscitation. The restoration of spontaneous circulation (ROSC) rate, 24-hour survival rate and 24-hour neurological function score were observed. RESULTS: There were no significant differences in all mentioned indexes between two groups at 10 minutes before and 10 minutes after asphyxia. At 2 minutes after the resuscitation, the MAP (mm Hg, 1 mm Hg = 0.133 kPa) and CPP (mm Hg) in CC-CPR group were significantly higher than those in ALC-CPR group (MAP: 43.60 ± 12.91 vs. 33.40 ± 6.59, P < 0.05; CPP: 21.67 ± 11.28 vs. 11.80 ± 4.16, P < 0.01), the VT (ml) and MV (L/min)in ALC-CPR group were significantly higher than those in CC-CPR group (VT: 111.67 ± 18.12 vs. 56.60 ± 7.76; MV: 11.17 ± 1.81 vs. 5.54 ± 0.79, both P < 0.01). At 5, 10, 20 minutes after resuscitation, in ALC-CPR group, pH value, arterial partial pressure of oxygen [PaO(2), mm Hg] and arterial oxygen saturation [SaO(2)] were increased, and HCO(3)(-) (mmol/L) and base excess (BE, mmol/L) were decreased, which significantly higher than those in CC-CPR group [pH at 20 minutes after resuscitation: 7.16 ± 0.16 vs. 7.01 ± 0.14; PaO(2): 82.73 ± 13.20 vs. 58.33 ± 17.77; HCO(3)(-): 27.71 ± 3.11 vs. 21.04 ± 3.62; BE: -4.78 ± 4.30 vs. -10.23 ± 2.12; SaO(2): 0.893 ± 0.088 vs. 0.764 ± 0.122], and arterial partial pressure of carbon dioxide [PaCO(2), mm Hg], K(+) (mmol/L) and lactic acid (Lac,mmol/L) were significantly lower than those in CC-CPR group [PaCO(2) at 20 minutes after resuscitation: 49.40 ± 15.60 vs. 79.80 ± 15.35; K(+): 7.18 ± 1.76 vs. 8.55 ± 1.02; Lac: 8.17 ± 1.46 vs. 10.39 ± 1.92], with statistical significant (P < 0.05 or P < 0.01). But the ROSC rate and 24-hour survival rate in ALC-CPR group were significantly higher than those in CC-CPR group (ROSC rate: 80.0% vs. 26.7%, P < 0.01; 24-hour survival rate: 60.0% vs. 13.3%, P < 0.05), and the 24-hour neurological function score was significantly lower than that in CC-CPR group (1.11 ± 0.33 vs. 3.50 ± 0.70, P < 0.01). CONCLUSION: In the incipient stage of cardiopulmonary resuscitation of the swine CA model of asphyxia, compared with CC-CPR, ALC-CPR can be more effective.

Influences of different drying methods on the structural characteristics and prebiotic activity of polysaccharides from bamboo shoot (Chimonobambusa quadrangularis) residues.

In the present study, in order to assess the influences of drying methods on the chemical structures, in vitro digestibility and prebiotic potential of polysaccharides extracted from Chimonobambusa quadrangularis shoot (CPSs), four drying methods, including hot air-, vacuum-, freeze-, and spray-drying, were utilized to dry CPSs. Results revealed that the physicochemical characteristics and prebiotic activity of CPSs varied by different drying methods. In comparison with the other drying methods, freeze-dried CPSs had higher uronic acid content (9.58%), lower medium-high molecular weight (117.63 kDa), smaller particle size (115.97 nm) and better solubility. All four CPSs fractions exhibited low degree of digestibility to pretended human gastric juice (< 2%) and α-amylase (< 5%). The freeze-dried CPSs showed the greatest prebiotic activity as this polysaccharide induced the strongest proliferation effect of probiotic bacteria and the highest production of total short chain fatty acids. Our results collectively provided substantial evidence that the freeze-drying method proposed in this study could be an effective technique in improving the prebiotic potentiality of CPSs.

Antibacterial Activity of Chrysanthemum buds Crude Extract Against Cronobacter sakazakii and Its Application as a Natural Disinfectant.

Cronobacter sakazakii is an opportunistic food-borne pathogen that endangers the health of neonates and infants. This study aims to elucidate the antibacterial activity and mechanism of Chrysanthemum buds crude extract (CBCE) against C. sakazakii and its application as a natural disinfectant. The antibacterial activity was evaluated by the determination of the diameter of inhibition zone (DIZ), minimum inhibitory concentration (MIC), and minimum bactericide concentration (MBC). The antibacterial mechanism was explored based on the changes of growth curve assay, intracellular ATP concentration, membrane potential, intracellular pH (pHin), content of soluble protein and nucleic acid, and cell morphology. Finally, the inactivation effects of CBCE against C. sakazakii in biofilm on stainless steel tube, tinplate, glass, and polystyrene were evaluated. The results showed that the DIZ, MIC, and MBC of CBCE against C. sakazakii were 14.55 ± 0.44-14.84 ± 0.38 mm, 10 mg/mL, and 20 mg/mL, respectively. In the process of CBCE acting on C. sakazakii, the logarithmic growth phase of the tested bacteria disappeared, and the concentrations of intracellular ATP, pHin, bacterial protein, and nucleic acid were reduced. Meanwhile, CBCE caused the cell membrane depolarization and leakage of cytoplasm of C. sakazakii. In addition, about 6.5 log CFU/mL of viable C. sakazakii in biofilm on stainless steel tube, tinplate, glass, and polystyrene could be inactivated after treatment with 1 MIC of CBCE for 30 min at 25°C. These findings reveal the antibacterial activity and mechanism of CBCE against C. sakazakii and provide a possibility of using a natural disinfectant to kill C. sakazakii in the production environment, packaging materials, and utensils.

Comparisons of prebiotic activity of polysaccharides from shoot residues of bamboo (Chimonobambusa quadrangularis) via different ethanol concentrations.

Three polysaccharide fractions from bamboo shoot (Chimonobambusa quadrangularis), CPS70, CPS75, and CPS80, were prepared using a final ethanol concentration of 70%, 75%, and 80% in the precipitation process. In vitro digestibility and the prebiotic activity of CPS70, CPS75, and CPS80 were evaluated and compared. The results indicated that all three of the CPS fractions exhibit a high degree of nondigestibility to human gastric juice (>98.5%) or α-amylase hydrolysis (>94.5%). Compared with the blank control, the three CPS fractions could not only significantly (p < .05) stimulate the proliferation of B. adolescentis, B. infantis, B. bifidum, and L. acidophilus, but also significantly (p < .05) enhance the production of lactic, acetic, propionic, and butyric acids when these polysaccharides were added as alternative carbon sources to glucose during the in vitro fermentation of four probiotics. Furthermore, when comparing the three CPS fractions, CPS75 displayed the strongest prebiotic potential, as this polysaccharide had the strongest effect on the proliferation of probiotic bacteria as well as the greatest effect on SCFAs production. These results demonstrated that the concentration of ethanol used during the precipitation process has a significant impact on the prebiotic activity of CPS. PRACTICAL APPLICATIONS: Ethanol precipitation is the first step when extracting polysaccharides from aqueous extracts as it is simple, rapid, and easy to carry out. This study focuses on how different concentrations of ethanol used in the precipitation process affect the prebiotic potential of bamboo shoot (Chimonobambusa quadrangularis) polysaccharides (CPS). The result indicated that the concentration of ethanol used during the precipitation process has a significant impact on the prebiotic activity of CPS. To our knowledge, it is the first to evaluate the effects of the concentration of ethanol during the process of precipitation on prebiotic potential of polysaccharides, which can subsequently be applied to the optimization of ethanol concentration when precipitating natural polysaccharides for the purpose of in vitro fermentation.

Different Numbers of Long-Pulse 1064-nm Nd-YAG Laser Treatments for Onychomycosis: A Pilot Study.

PURPOSE: To examine the benefits of different numbers of 1064-nm Nd-YAG laser treatments in patients with onychomycosis. METHODS: This was a pilot study of patients with onychomycosis who were divided into three groups: four treatment sessions (group A), eight sessions (group B), and 12 sessions (group C). Only infected nails of degrees II-III (Scoring Clinical Index for Onychomycosis) were included. Treatment was given once a week using a long-pulse Nd-YAG 1064-nm laser. Patients were followed at 8, 16, and 24 weeks after the first treatment. Side effects were recorded. RESULTS: Treatments were completed for 442 nails in 102 patients. The efficacy rates at 8, 16, and 24 weeks were 35.5%, 38.7%, and 37.4% for group A; 31.4%, 41.7%, and 44.0% for group B; and 27.7%, 50.0%, and 55.4% for group C, respectively. There was a significant difference in the efficacy rate at 24 weeks (P = 0.016) between groups A and C, but not for groups A vs. B, or for groups B vs. C. No difference in the efficacy rate at 8 or 16 weeks was observed among the three groups. In all three groups, the efficacy was better for degree II nails than for degree III nails (all P = 0.016) between groups A and C, but not for groups A vs. B, or for groups B vs. C. No difference in the efficacy rate at 8 or 16 weeks was observed among the three groups. In all three groups, the efficacy was better for degree II nails than for degree III nails (all. CONCLUSIONS: The 1064-nm Nd-YAG laser had clinical benefits against onychomycosis. Higher numbers of treatments provided better long-term (24-week) benefits, but had no impact on the short-term outcomes. The efficacy of laser treatment on degree II onychomycosis was better than for degree III.

Fur Represses Vibrio cholerae Biofilm Formation via Direct Regulation of vieSAB, cdgD, vpsU, and vpsA-K Transcription.

Attached Vibrio cholerae biofilms are essential for environmental persistence and infectivity. The vps loci (vpsU, vpsA-K, and vpsL-Q) are required for mature biofilm formation and are responsible for the synthesis of exopolysaccharide. Transcription of vps genes is activated by the signaling molecule bis-(3'-5')-cyclic di-GMP (c-di-GMP), whose metabolism is controlled by the proteins containing the GGDEF and/or EAL domains. The ferric uptake regulator (Fur) plays key roles in the transcription of many genes involved in iron metabolism and non-iron functions. However, roles for Fur in Vibrio biofilm production have not been documented. In this study, phenotypic assays demonstrated that Fur, independent of iron, decreases in vivo c-di-GMP levels and inhibits in vitro biofilm formation by Vibrio cholerae. The Fur box-like sequences were detected within the promoter-proximal DNA regions of vpsU, vpsA-K, vieSAB, and cdgD, suggesting that transcription of these genes may be under the direct control of Fur. Indeed, the results of luminescence, quantitative PCR (qPCR), electrophoretic mobility shift assay (EMSA), and DNase I footprinting assays demonstrated Fur to bind to the promoter-proximal DNA regions of vpsU, vpsA-K, and cdgD to repress their transcription. In contrast, Fur activates the transcription of vieSAB in a direct manner. The cdgD and vieSAB encode proteins with GGDEF and EAL domains, respectively. Thus, data presented here highlight a new physiological role for Fur wherein it acts as a repressor of V. cholerae biofilm formation mediated by decreasing the production of exopolysaccharide and the intracellular levels of c-di-GMP.

All the Right Noises: Background Variability Helps Early Word Learning.

Variability is prevalent in early language acquisition, but, whether it supports or hinders learning is unclear; while target variability has been shown to facilitate word learning, variability in competitor items has been shown to make the task harder. Here, we tested whether background variability could boost learning in a referent selection task. Two groups of 2-year-old children saw arrays of one novel and two known objects on a screen, and they heard a novel or known label. Stimuli were identical across conditions, with the exception that in the constant color condition objects appeared on a uniform white background, and in the variable color condition backgrounds were different, uniform colors. At test, only children in the variable condition showed evidence of retaining label-object associations. These data support findings from the adult memory literature, which suggest that variability supports learning by decontextualizing representations. We argue that these data are consistent with dynamic systems accounts of learning in which low-level entropy adds sufficient noise to the developmental system to precipitate a change in behavior.

Comparative genomics of type 1 IncC plasmids from China.

AIM: This study dealt with genomic characterization of type 1 IncC resistance plasmids, capable of spreading across taxonomic borders, from China. MATERIALS & METHODS: p112298-tetA was sequenced and compared with type 1 IncC reference plasmid pR148 and two available sequenced type 1 IncC plasmids pHS36-NDM and pVAS3-1 from China. RESULTS: These plasmids contained one or more exogenous resistance islands, which included the ARI-A islands, the ARI-B islands, the ISEcp1-blaCMY units and the bla KPC-2 region and were inserted at various sites in the IncC backbone and thus represented three distinct lineages. CONCLUSION: Complex rearrangement and homologous recombination events have occurred during evolution of p112298-tetA, making it significantly differ modularly from the other three plasmids with respect to both plasmid backbone and exogenous resistance regions.

Effect of stem cell-based therapy for ischemic stroke treatment: A meta-analysis.

Stroke is a major cause of death and long-term disability worldwide. Cell-based therapies improve neural functional recovery in pre-clinical studies, but clinical results require evaluation. We aimed to assess the effects of mesenchymal stem cells on ischemic stroke treatment. We searched the PubMed, Embase and Cochrane databases until July 2015 and selected the controlled trials using mesenchymal stem cells for ischemic stroke treatment compared with cell-free treatment. We assessed the results by meta-analysis using the error matrix approach, and we assessed the association of mesenchymal stem cell counts with treatment effect by dose-response meta-analysis. Seven trials were included. Manhattan plots revealed no obvious advantage of the application of stem cells to treat ischemic stroke. For the comprehensive evaluation index, stem cell treatment did not significantly reduce the mortality of ischemic stroke patients (relative risk (RR) 0.59, 95% confidence interval (CI) 0.29-1.19; ln(RR) 0.54, 95% CI -0.18 to 1.25, p=0.141). The National Institutes of Health Stroke Scale was also not significantly improved by stem cell treatment (standardized mean difference (SMD) 0.94, 95% CI -0.13 to 2.01, p=0.072). The European Stroke Scale was significantly improved using the stem cell treatment (SMD 1.15, 95% CI 0.37-1.92). The dose-response meta-analysis did not reveal a significant linear regression relationship between the number of stem cells and therapeutic effect, except regarding the National Institutes of Health Stroke Scale index. In conclusion, our assessments indicated no significant difference between stem cell and cell-free treatments. Further research is needed to discover more effective stem cell-based therapies for ischemic stroke treatment.

[Effect of anisodamine on myocardial connexin 43 expression in pig after resuscitation from cardiac arrest].

OBJECTIVE: To investigate the effect of anisodamine on the expression of connexin 43 (Cx43) in swine ventricular myocardium after resuscitation from cardiac arrest. METHODS: The experiment was conducted on healthy pigs, and they were randomly divided into three groups, namely sham group, epinephrine group (control group) and anisodamine group (experimental group, animals were resuscitated combined with injection of 0.4 mg/kg of anisodamine), with 5 pigs in each group. Model of ventricular fibrillation was reproduced by alternating current challenge, and cardiopulmonary resuscitation (CPR) was performed 8 minutes after cardiac arrest. Left ventricular myocardium was harvested at 24 hours after restoration of spontaneous circulation. The expression and distribution of Cx43 were observed by immunofluorescence, Cx43 mRNA expression was assessed with reverse transcription-polymerase chain reaction (RT-PCR), and the protein expressions of Cx43 and phosphorylation of Cx43 (p-Cx43) were analyzed by Western Blot. RESULTS: The positive expression of Cx43 in ventricular muscle was distributed uniformly, mostly at the end-to-end linkage of myocardial cells, with a few side-to-side linkage in sham group. The positive expression of Cx43 in control group was significantly weaker than that in the sham group, and the signal intensity was significantly declined (4.35±2.10 vs. 10.02±3.66, P < 0.01). The positive expression of Cx43 at the end-to-end linkage and side-to-side linkage was irregular in experimental group, and the signal intensity was obviously higher than that in the control group (7.91±2.54 vs. 4.35±2.10, P < 0.05), but it was significantly weaker than that in the sham group (7.91±2.54 vs. 10.02±3.66, P < 0.05). For control group and experimental group, the Cx43 mRNA and protein expressions were significantly lower than those of the sham group [Cx43 mRNA (A value): 0.32±0.05, 0.32±0.03 vs. 0.48±0.07; Cx43 protein (A value): 0.43±0.03, 0.50±0.07 vs. 0.65±0.04, all P < 0.01], and there were no significant differences between experimental group and control group (all P > 0.05). The p-Cx43 protein expression of control group was significantly lower than that of the sham group (A value: 0.22±0.03 vs. 0.37±0.06, P < 0.01), and it was significantly higher in the experiment group than that in the control group (A value: 0.29±0.07 vs. 0.22±0.03, P < 0.01), but there was no significant difference with the sham group (P > 0.05). No significant difference in p-Cx43/Cx43 was found among sham, control, and experiment groups (0.57±0.09, 0.51±0.05, 0.58±0.06, all P > 0.05). CONCLUSIONS: Anisodamine can improve the abnormal expression of Cx43 in ventricular muscle of pigs with cardiac arrest, which may be related to the protection effect of anisodamine on cardiac conduction.

[Effects of interrupted abdominal aorta compression on cardiopulmonary cerebral resuscitation after cardiac arrest in rabbit].

OBJECTIVE: To explore the effect of the interrupted abdominal aorta compression after cardiopulmonary resuscitation (IAAC-CPR) on cardiopulmonary cerebral resuscitation in a rabbit model of cardiac arrest (CA). METHODS: According to the random number table, 10 New Zealand rabbits of both genders were equally divided into the chest compression-cardiopulmonary resuscitation (CC-CPR) group or IAAC-CPR group, with 5 rabbits in each group. CA model was reproduced by injection of iced-potassium chloride into the jugular vein and obstruction of trachea to produce asphyxia. CA was maintained for 3 minutes before cardiopulmonary resuscitation(CPR). CC-CPR was performed with assisted ventilation + chest compression, while IAAC-CPR was performed by the way of assisted ventilation + chest compressions + compressions on abdominal aorta. The hemodynamics and cerebral cortex blood flow were observed during resuscitation. Time of return of spontaneous circulation (ROSC), 24-hour survival rates, and scores of neurological function, and situation of abdominal organs were recorded. RESULTS: At 30, 60, 90 and 120 seconds after CPR, the cerebral blood flow (CBF, PU value) and mean arterial pressure (MAP, mmHg, 1 mmHg=0.133 kPa) of IAAC-CPR group were significantly higher than those of CC-CPR group (CBF 30 seconds: 16.1 ± 6.0 vs. 7.8 ± 2.2, 60 seconds: 91.6 ± 11.8 vs. 57.3 ± 23.2, 90 seconds: 259.9 ± 74.9 vs. 163.6 ± 50.3, 120 seconds: 301.5 ± 60.5 vs. 208.4 ± 23.8; MAP 30 seconds: 46.4 ± 9.4 vs. 31.4 ± 8.7, 60 seconds: 55.8 ± 13.8 vs. 34.0 ± 11.5, 90 seconds: 61.2 ± 11.5 vs. 38.2 ± 10.1, 120 seconds: 63.6 ± 11.8 vs. 40.2 ± 10.2, all P<0.05). Compared with CC-CPR group, in IAAC - CPR group, the time necessary for ROSC was obviously shortened (seconds: 182.0 ± 59.0 vs. 312.6 ± 86.6, t=2.787, P=0.024), 24-hour nerve function score was significantly lowered (2.4 ± 1.7 vs. 4.6 ± 0.6, t = 2.974, P = 0.023). The successful recovery rate (80.0% vs. 60.0%, χ² = 0.000, P=1.000) and 24-hour survival rate (80.0% vs. 40.0%, χ² = 0.417, P=0.519) were significantly increased, but without statistical significance. No liver damage was found at 24 hours after ROSC. CONCLUSIONS: In the early recovery of CA in rabbit, IAAC-CPR can result in better cerebral blood flow perfusion as compared with CC-CPR, and it significantly reduced damage to the nervous system function without producing abdominal organ damage.

[The impact of interrupted abdominal aorta compression on resuscitation effects of cardiac arrest rabbit].

OBJECTIVE: To determine whether interrupted abdominal aorta compression-cardiopulmonary resuscitation (IAAC-CPR), as a new cardiopulmonary resuscitation (CPR) method, can improve resuscitation effects on rabbits with cardiac arrest (CA). METHODS: Twenty-eight New Zealand rabbits were randomly divided into two groups in equal number (n=14), and they were resuscitated either by standard CPR (STD-CPR, external chest compression) or by IAAC-CPR (abdominal aorta compression at intermission of external chest compression). CA model was reproduced by injection of iced-potassium chloride, and it was maintained for 3 minutes before resuscitation. Electrocardiogram (ECG), hemodynamic indexes were monitored continuously. Aortic systolic pressure and right atrial pressure at baseline and during resuscitation were recorded. Mean arterial pressure (MAP), coronary perfusion pressure (CPP) and recovery of spontaneous circulation (ROSC) indexes were compared between two groups. RESULTS: Compared with STD-CPR group, MAP within 2 minutes of resuscitation (without drugs intervention) in the IAAC-CPR group was significantly increased (30 s: 46.0±12.6 mm Hg vs. 30.0±12.2 mm Hg, 60 s: 57.0±15.6 mm Hg vs. 31.9±9.7 mm Hg, 90 s: 61.9±14.4 mm Hg vs. 36.0±9.8 mm Hg, 120 s: 63.1±12.6 mm Hg vs. 37.8±11.1 mm Hg, all P<0.05), and CPP was also significantly increased (30 s: 29.9±17.4 mm Hg vs. 14.1±11.0 mm Hg, 60 s: 43.1±22.4 mm Hg vs. 14.3±9.8 mm Hg, 90 s: 46.7±20.1 mm Hg vs. 15.9±7.7 mm Hg, 120 s: 50.5±21.0 mm Hg vs. 17.3±9.9 mm Hg, all P<0.05), the time of ROSC was earlier (212.1±43.4 s vs. 307.3±51.2 s, P<0.05), and successful resuscitation rate was significantly higher (85.7% vs. 42.8%, P<0.05). However, there were no statistical differences in ROSC rate and the survivor rate at 24 hours and 48 hours between the two groups, though they were increased. No abdominal organs injury was found in all animals by postmortem study. CONCLUSION: Abdominal aorta compression in the intermittent period of chest compression (IAAC-CPR) increases MAP, CPP and the successful rate of resuscitation, thus improves the outcome.

[Effect of urokinase on cerebral perfusion in rabbits after cardiopulmonary resuscitation].

OBJECTIVE: To investigate the effect of urokinase on cerebral microcirculatory perfusion after cardiopulmonary resuscitation (CPR) in rabbits after cardiac arrest (CA). METHODS: Twenty New Zealand rabbits were assorted into drug thrombolysis group and routine CPR group by randomized digital method with 10 in each group. Potassium chloride injection combined with asphyxia was employed to establish the CA model, CPR and basic life-support were performed in routine CPR group. Following the above treatments, 20 kU/kg urokinase was given in thrombolysis group. The relative cerebral blood flow (rCBF), cerebral blood volume (rCBV) and top teep time (rTTP) were observed by dual-slice spiral CT cerebral perfusion imaging in order to investigate the effect of urokinase on cerebral microcirculatory perfusion in rabbits. RESULTS: rCBF and rCBV in thrombolysis group were significantly higher than those in routine CPR group (rCBF: 1.248±0.139 vs 0.900±0.070, t=6.870, P=0.000; rCBV: 1.206±0.117 vs. 0.969±0.067, t=6.156, P=0.000), and rTTP in thrombolysis group was significantly shorter than that in routine CPR group (0.950±0.037 vs. 1.015±0.026, t=3.777, P=0.004). The cerebral perfusion in thrombolysis group was obviously better than routine CPR group. There were no significant differences in the time for restoration of spontaneous circulation (ROSC), the time for restoration of spontaneous breathing or mean arterial pressure (MAP between routine CPR group and thrombolysis group [ time of ROSC (s): 307.9±96.4 vs. 242.0±71.0, t=-1.741, P=0.099; time of restoration of spontaneous breathing (minutes): 20.6±12.5 vs. 19.3±10.1, t= -0.256, P=0.801; MAP (mm Hg, 1 mm Hg=0.133 kPa): 65.5 = 6.2 vs 69.0±6.7, t=1.217, P=0.239]. CONCLUSION: Thrombolytic therapy with urokinase in CPR could improve the cerebral microcirculatory perfusion in CA rabbits.