CCL2 Potentiates Inflammation Pain and Related Anxiety-Like Behavior Through NMDA Signaling in Anterior Cingulate Cortex

Previous studies have shown that the C-C motif chemokine ligand 2 (CCL2) is widely expressed in the nervous system and involved in regulating the development of chronic pain and related anxiety-like behaviors, but its precise mechanism is still unclear. This paper provides an in-depth examination of the involvement of CCL2-CCR2 signaling in the anterior cingulate cortex (ACC) in intraplantar injection of complete Freund's adjuvant (CFA) leading to inflammatory pain and its concomitant anxiety-like behaviors by modulation of glutamatergic N-methyl-D-aspartate receptor (NMDAR). Our findings suggest that local bilateral injection of CCR2 antagonist in the ACC inhibits CFA-induced inflammatory pain and anxiety-like behavior. Meanwhile, the expression of CCR2 and CCL2 was significantly increased in ACC after 14 days of intraplantar injection of CFA, and CCR2 was mainly expressed in excitatory neurons. Whole-cell patch-clamp recordings showed that the CCR2 inhibitor RS504393 reduced the frequency of miniature excitatory postsynaptic currents (mEPSC) in ACC, and CCL2 was involved in the regulation of NMDAR-induced current in ACC neurons in the pathological state. In addition, local injection of the NR2B inhibitor of NMDAR subunits, Ro 25-6981, attenuated the effects of CCL2-induced hyperalgesia and anxiety-like behavior in the ACC. In summary, CCL2 acts on CCR2 in ACC excitatory neurons and participates in the regulation of CFA-induced pain and related anxiety-like behaviors through upregulation of NR2B. CCR2 in the ACC neuron may be a potential target for the treatment of chronic inflammatory pain and pain-related anxiety.

Peripheral BDNF Regulates Somatosensory-Sympathetic Coupling in Brachial Plexus Avulsion-Induced Neuropathic Pain

Brachial plexus avulsion (BPA) is a combined injury involving the central and peripheral nervous systems. Patients with BPA often experience severe neuropathic pain (NP) in the affected limb. NP is insensitive to the existing treatments, which makes it a challenge to researchers and clinicians. Accumulated evidence shows that a BPA-induced pain state is often accompanied by sympathetic nervous dysfunction, which suggests that the excitation state of the sympathetic nervous system is correlated with the existence of NP. However, the mechanism of how somatosensory neural crosstalk with the sympathetic nerve at the peripheral level remains unclear. In this study, through using a novel BPA C7 root avulsion mouse model, we found that the expression of BDNF and its receptor TrκB in the DRGs of the BPA mice increased, and the markers of sympathetic nervous system activity including α1 and α2 adrenergic receptors (α1-AR and α2-AR) also increased after BPA. The phenomenon of superexcitation of the sympathetic nervous system, including hypothermia and edema of the affected extremity, was also observed in BPA mice by using CatWalk gait analysis, an infrared thermometer, and an edema evaluation. Genetic knockdown of BDNF in DRGs not only reversed the mechanical allodynia but also alleviated the hypothermia and edema of the affected extremity in BPA mice. Further, intraperitoneal injection of adrenergic receptor inhibitors decreased neuronal excitability in patch clamp recording and reversed the mechanical allodynia of BPA mice. In another branch experiment, we also found the elevated expression of BDNF, TrκB, TH, α1-AR, and α2-AR in DRG tissues from BPA patients compared with normal human DRGs through western blot and immunohistochemistry. Our results revealed that peripheral BDNF is a key molecule in the regulation of somatosensory-sympathetic coupling in BPA-induced NP. This study also opens a novel analgesic target (BDNF) in the treatment of this pain with fewer complications, which has great potential for clinical transformation.

Ultrasensitive Detection of Bacteria Using a 2D MOF Nanozyme-Amplified Electrochemical Detector

Bacterial infection is one of the major causes of human death worldwide. To prevent bacterial infectious diseases from spreading, it is of critical importance to develop convenient, ultrasensitive, and cost-efficient methods for bacteria detection. Here, an electrochemical detector of a functional two-dimensional (2D) metal-organic framework (MOF) nanozyme was developed for the sensitive detection of pathogenic Staphylococcus aureus. A dual recognition strategy consisting of vancomycin and anti-S. aureus antibody was proposed to specifically anchor S. aureus. The 2D MOFs with excellent peroxidase-like activity can efficiently catalyze o-phenylenediamine to 2,2-diaminoazobenzene, which is an ideal electrochemical signal readout for monitoring the bacteria concentration. Under optimal conditions, the present bioassay provides a wide detection range of 10-7.5 × 10⁷ colony-forming units CFU/mL with a detection limit of 6 CFU/mL, which is better than most of the previous reports. In addition, the established electrochemical sensor can selectively and accurately identify S. aureus in the presence of other bacteria. The present work provides a new pathway for sensitive and selective detection of S. aureus and presents a promising potential in the realm of clinical diagnosis.

In Situ Fabrication of Ultrasmall Gold Nanoparticles/2D MOFs Hybrid as Nanozyme for Antibacterial Therapy

As one of the common reactive oxygen species, H₂ O₂ has been widely used for combating pathogenic bacterial infections. However, the high dosage of H₂ O₂ can induce undesired damages to normal tissues and delay wound healing. In this regard, peroxidase-like nanomaterials serve as promising nanozymes, thanks to their positive promotion toward the antibacterial performance of H₂ O₂ , while avoiding the toxicity caused by the high concentrations of H₂ O₂ . In this work, ultrasmall Au nanoparticles (UsAuNPs) are grown on ultrathin 2D metal-organic frameworks (MOFs) via in situ reduction. The formed UsAuNPs/MOFs hybrid features both the advantages of UsAuNPs and ultrathin 2D MOFs, displaying a remarkable peroxidase-like activity toward H₂ O₂ decomposition into toxic hydroxyl radicals (·OH). Results show that the as-prepared UsAuNPs/MOFs nanozyme exhibits excellent antibacterial properties against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria with the assistance of a low dosage of H₂ O₂ . Animal experiments indicate that this hybrid material can effectively facilitate wound healing with good biocompatibility. This study reveals the promising potential of a hybrid nanozyme for antibacterial therapy and holds great promise for future clinical applications.

Biomimetic Nanochannel-Ionchannel Hybrid for Ultrasensitive and Label-Free Detection of MicroRNA in Cells

A biomimetic nanochannel-ionchannel hybrid coupled with electrochemical detector was developed for label-free and ultrasensitive detection of microRNA (miRNA) in cells. Probe single stranded DNA (ssDNA) was first immobilized on the outer surface of the nanochannel-ionchannel hybrid membrane, which can hybridize with the target miRNA in cells. Due to the unique mass transfer property of the hybrid, the DNA-miRNA hybridization kinetics can be sensitively monitored in real-time using the electrochemical technique. More importantly, due to the super small size of the ionchannels, the DNA probe immobilization and hybridization process can be carried out on the outer surface of the ionchannel side, which can effectively avoid the blockage and damage of channels and thus considerably enhance the reproducibility and accuracy of the method. Using this strategy, the miRNA ranging from 0.1 fM to 0.1 μM can be facilely detected with a low detection limit of 15.4 aM, which is much lower than most reported work. The present strategy provides a sensitive and label-free miRNA detection platform, which will be of great significance in biomedical research and clinical diagnosis.

Increased Vitreous Chemerin Levels Are Associated with Proliferative Diabetic Retinopathy

PURPOSE

To investigate chemerin in the vitreous bodies of patients with proliferative diabetic retinopathy (PDR) and determine the correlation between the levels of vitreous chemerin and vascular endothelial growth factor (VEGF).

METHODS

This study included 17 patients suffering from PDR and vitreous hemorrhage (VH) (group A), 21 patients with PDR and tractional retinal detachment (TRD) (group B) and 25 patients with idiopathic macular holes or preretinal membranes (control group). All vitreous samples were obtained through pars plana vitrectomy. Enzyme-linked immunosorbent assay and Western blot analysis were performed to evaluate the levels of vitreous chemerin and VEGF.

RESULTS

Vitreous concentrations of chemerin were significantly higher in PDR patients with VH and TRD than those in the controls [4.82 ng/ml (3.91-6.13) vs. 5.03 ng/ml (4.01-6.15) vs. 2.53 ng/ml (1.53-5.66), p = 0.025]. The ratio of vitreous chemerin to plasma chemerin concentration significantly differed between groups A and B and the control group [4.93% (4.69-5.34) vs. 4.98% (4.63-5.19) vs. 2.58% (1.78-4.58), p < 0.001]. Western blot results indicated that the levels of vitreous chemerin protein in PDR patients significantly increased compared with those in the controls. Spearman correlation analysis further showed that vitreous chemerin levels in patients with PDR were positively correlated with vitreous VEGF levels (r = -0.542, p < 0.001).

CONCLUSIONS

Increased vitreous chemerin levels are associated with the development of PDR.

[Population dynamics of ground carabid beetles and spiders in a wheat field along the wheat-alfalfa interface and their response to alfalfa mowing]

Taking the wheat-alfalfa and wheat-wheat interfaces as model systems, sampling points were set by the method of pitfall trapping in the wheat field at the distances of 3 m, 6 m, 9 m, 12 m, 15 m, 18 m, 21 m, 24 m, and 27 m from the interface. The species composition and abundance of ground carabid beetles and spiders captured in pitfalls were investigated. The results showed that, to some extent there was an edge effect on species diversity and abundance of ground carabid beetles and spiders along the two interfaces. A marked edge effect was observed between 15 m and 18 m along the alfalfa-wheat interface, while no edge effect was found at a distance over 20 m. The edge effect along the wheat-wheat interface was weaker in comparison to the alfalfa-wheat interface. Alfalfa mowing resulted in the migration of a large number of ground carabid beetles and spiders to the adjacent wheat filed. During ten days since mowing, both species and abundance of ground carabid beetles and spiders increased in wheat filed within the distance of 20 m along the alfalfa-wheat interface. The spatial distribution of species diversity of ground beetles and spiders, together with the population abundance of the dominant Chlaenius pallipes and Pardosa astrigera, were depicted, which could directly indicate the migrating process of natural enemy from alfalfa to wheat field.

G1359A polymorphism in the cannabinoid receptor-1 gene is associated with metabolic syndrome in the Chinese Han population

BACKGROUND AND AIMS

Recent studies suggest that endocannabinoids modulate food intake and lipogenesis through cannabinoid receptor-1 (CNR1). This study aims to determine the association between G1359A polymorphism of CNR1 and metabolic syndrome (MetS) in the Chinese Han population.

METHODS

A total of 382 subjects at risk for MetS and 136 healthy subjects from Tianjin, China were genotyped for the G1359A polymorphism of CNR1 using TaqMan assay. Anthropometric measurements and serum analyses were done for body mass index (BMI), waist circumference, blood pressure, serum triglycerides (TG), serum total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting plasma glucose, and plasma insulin levels.

RESULTS

GG genotype of CNR1 has a higher incidence in MetS subjects than in control subjects. Logistic regression analysis shows that the GG genotype was significantly associated with the increased risk of developing MetS (OR 2.204, 95% CI 1.277-3.803, p = 0.005). Compared with CNR1 GG genotype in MetS subjects, CNR1 GA and AA genotypes in subjects with MetS had relatively lower levels of BMI, waist circumference, homeostasis model assessment of insulin resistance (HOMA-IR) and TG.

CONCLUSIONS

Results suggest that the G1359A polymorphism of the CNR1 gene may contribute to MetS susceptibility in the Chinese Han population.

Afferent nerve sensitivity is decreased by an iNOS-dependent mechanism during indomethacin-induced inflammation in the murine jejunum in vitro

Evidence exists that visceral afferent sensitivity is subject to regulatory mechanisms. We hypothesized that afferent sensitivity is decreased in the small intestine during intestinal inflammation by an inducible nitric oxide synthase (iNOS)-dependent mechanism. C57BL/6 mice were injected twice with vehicle or 60 mg kg(-1) indomethacin subcutaneously to induce intestinal inflammation. Afferent sensitivity was recorded on day 3 from a 2-cm segment of jejunum in vitro by extracellular multi-unit afferent recordings from the mesenteric nerve bundle. In subgroups (n = 6), iNOS was inhibited selectively by L-N6-(1-iminoethyl)-lysine (L-NIL) given either chronically from day 1-3 (3 mg kg(-1) twice daily i.p.) or acutely into the organ bath (30 micromol L(-1)). The indomethacin-induced increase of macroscopic and microscopic scores of intestinal inflammation (both P < 0.05) were unchanged after pretreatment with L-NIL. Peak afferent firing following bradykinin (0.5 micromol L(-1)) was 55 +/- 8 impulse s(-1) during inflammation vs 97 +/- 7 impulse s(-1) in controls (P < 0.05). Normal firing rate was preserved following L-NIL pretreatment (112 +/- 16 impulse s(-1)) or acute administration of L-NIL (108 +/- 14 impulse s(-1)). A similar L-NIL dependent reduction was observed for 5-HT (250 micromol L(-1)) and mechanical ramp distension from 20 to 60 cmH(2)O (both P < 0.05). Intraluminal pressure peaks were decreased to 0.66 +/- 0.1 cmH(2)O during inflammation compared to 2.51 +/- 0.3 in controls (P < 0.01). Afferent sensitivity is decreased by an iNOS-dependent mechanism during intestinal inflammation which appears to be independent of the inflammatory response. This suggests that iNOS-dependent nitric oxide production alters afferent sensitivity during inflammation by interfering with signal transduction to afferent nerves rather than by attenuating intestinal inflammation.

The effect of data reduction by independent component analysis and principal component analysis in hand motion identification

Both independent component analysis (ICA) and principal component analysis (PCA) were used in this study to evaluate their effects in data reduction in the hand motion identification using surface electromyogram (SEMG) and stationary wavelet transformation. The results indicate that both methods increase the number of training epochs of the artificial neural network. The unsupervised fast ICA reduces the number of SEMG channels from 7 to 4. However the hand motion identification rate using the reduced channels is significantly lower (p < 0.05). On the other hand, the PCA reduces the size of neural network by more than 70%. Moreover, the results of discrimination rate and neural network training epochs show no significant difference as compared to the results before PCA reduction. The result of this study demonstrates that using wavelet and PCA are effective pre-processing for surface EMG analysis. It can efficiently reduce the size of neural network and increase the discrimination rate for different hand motions.

Computer system for four-dimensional transesophageal echocardiographic image reconstruction

This paper presents a system for reconstructing a four-dimensional (4D) heart-beating image from transesophageal echocardiographic (TEE) data acquired with a rotational approach. The system consists of the necessary processing modules for two-dimensional (2D) echocardiogram reformation and 3D/4D-image reconstruction. These include the modules of image decoding, image re-coordinating, and three-dimensional (3D) volume rendering. The system is implemented under PC platform with Windows 95 operating system (with Intel Pentium-166 CPU, 64 MB RAM on board, and 2.0 GB hard disk capacity). It takes 6 min to reconstruct a 4D echocardiographic data set. The resultant 2D/3D/4D echocardiographic image provide the tools for investigating the phenomenon of heart beating, exploring the heart structure, and reformatting the 2D echocardiograms in an arbitrary plane. The functions provided by the system can be applied for further studies, such as 3D cardiac shape analysis, cardiac function measurement, and so forth.

A graphic orientated data analysis system for hemodynamic research

A software program to process and to extract physiological functional hemodynamics data has been developed and reported. The purpose of this software system is to process and capture cardiovascular hemodynamics and physiological functional data after data acquisition. The system utilized an interactive graphic display and script control to extract the data. With a minimum interface, it is capable of analyzing multiple channels of data and simultaneously obtaining the results. The extracted data includes global cardiovascular functional parameters and with script process the software will calculate stroke work from the pressure length relationship. The results are stored in files for further statistical analysis. The procedures are reliable and readily applicable to examine and analyze the acquired data with minimal observer bias.

A methodological improvement and system validation to obtain precise behavioral parameters for schedule-induced polydipsia

A Schedule-Induced Polydipsia (SIP) animal behaviors monitor system was devised. The system included a software package to acquire data and to format the data storage of the animal behavior in the experiment was designed. Data analysis software will also extract the necessary information from recorded data. The SIP experimental apparatus consists of a number of subsystems. They are operant chambers, event counters, signal acquisition and storage system. The operant chamber is equipped with hopper, pellet and lick sensor and locomotion detector. The data acquisition and storage subsystem are custom designed that run on IBM-PC. The discrete time markers for pellet drop, bar pressing and licking water were recorded at 200 Hz. The image of rat locomotion was recorded at 10 Hz. A test of four different stages of animal to verify the accuracy of the system was reported in this article. The food-deprived rats that were exposed to the intermittent food schedule (1 per minute) exhibit an excess drinking behavior. The animal behaviors that were monitored during the scheduled events are adjunctive, facultative and terminal behavior. The volume of water intake was also recorded for reference. The real time data is stored chronologically into two types of data file. Therefore, a special data analysis procedure is designed to extract the results for off-line statistic analysis. The extracted parameters for animal behaviors analyzing including drinking efficiency, inter-lick intervals, number of drinking bursts, size of burst, temporal distribution of licking, temporal distribution of bar pressing and locomotion. The system can be employed in many different SIP studies such as investigating the effect of acute and chronic influence of amphetamine.

Pacing-induced left ventricular asynchronies in dogs with critical coronary stenosis: mechanisms and effect of anesthetics

The mechanisms leading to left ventricular (LV) asynchronies are incompletely understood, and reports on the functional significance of asynchronies for the affected segments are conflicting. To characterize LV asynchronies, 16 anesthetized dogs with critical stenosis of the left anterior descending coronary artery (LAD) were instrumented to measure subendocardial contractile function (sonomicrometry) and the ECG in the LAD territory. The subendocardial ECG was also recorded from the anterior basal LV territory. Time of regional S wave arrival (TS) and time of onset of segment shortening were determined. The animals underwent atrial pacing with increasing frequencies until systolic LAD territory contractile dysfunction and eventual LV asynchronies were observed. Six animals without LAD stenosis served as controls to define the normal response (mean +/- 2.SD) to increasing pacing rates of systolic shortening and onset time of segment shortening (time difference between TS and onset of segment shortening). LAD contractile dysfunction was considered as a systolic shortening below the normal range, and LV asynchronies as an onset time of segment shortening above the normal range. When LV asynchronies occurred, onset time of segment shortening in the LAD territory was 80.1 +/- 4.9 ms versus 14.8 +/- 3.7 ms at control (P < 0.01); the time difference between S wave arrival in the LAD and circumflex territories, however, was unchanged. LV asynchronies were associated with marked LAD territory contractile dysfunction (systolic shortening of 9.6 +/- 0.8% v 21.0 +/- 1.9% at control, after systolic shortening of 31.3 +/- 3.8% v 9.0 +/- 2.6% at control; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute isovolemic hemodilution and blood transfusion. Effects on regional function and metabolism in myocardium with compromised coronary blood flow

The use of isovolemic hemodilution to prevent adverse side effects of homologous blood transfusions has increased. The lowest level of hemoglobin that can be tolerated without regional myocardial dysfunction, however, had not been precisely defined for left ventricular myocardium with compromised coronary blood flow. This level was determined in our study in 19 dogs with critical stenosis of the left anterior descending coronary artery during graded isovolemic hemodilution. Regional function was assessed by sonomicrometry in the territory supplied by the left anterior descending coronary artery, as well as in two noncompromised left ventricular areas; oxygen extraction and consumption in the left anterior descending coronary artery region were assessed by analysis of anterior descending coronary venous oxygen saturation. The median lowest level of hemoglobin tolerated without contractile dysfunction of the territory supplied by the left anterior descending artery was 7.5 gm/dl, with lower and upper quartiles of 6 and 9 gm/dl. In addition to a marked increase in cardiac output and transstenotic left anterior descending flow, global cardiac and regional myocardial functions were unchanged at a hemoglobin level of 7.5 gm/dl, as compared with a control level of hemoglobin of 12.0 +/- 0.4 gm/dl. At a mean level of hemoglobin of 6.0 +/- 0.4 gm/dl, marked contractile dysfunction developed in the left anterior descending region: Systolic shortening decreased from 24.2% +/- 2.1% to 17.9% +/- 1.9% (p < 0.01); postsystolic shortening increased from 4.0% +/- 3.0% to 12.2% +/- 3.8% (p < 0.01); and in the left anterior descending region, oxygen consumption decreased. The increase of arterial level of hemoglobin by only 1.9 +/- 0.2 gm/dl restored contractile function in the left anterior descending region, regional oxygen consumption, and oxygen extraction across the left anterior descending region. Moderate isovolemic hemodilution is relatively well tolerated in left ventricular myocardium with compromised coronary blood flow, and hemodilution regional contractile dysfunction induced by hemodilution is reversible by minimal blood transfusion.

Validation of 133Xe clearance as a cerebral blood flow measurement technique during cardiopulmonary bypass

133Xe clearance to measure cerebral blood flow (CBF) was examined in 10 dogs during cardiopulmonary bypass. As a reference method, a continuous Kety-Schmidt technique (CBFKS) with 133Xe as indicator was used. Extracranial tissue was removed to directly place the 133Xe detectors on the skull, and the head was covered with a 3 mm lead shield to minimize contamination of the 133Xe clearance curve with extracranial radiation. 133Xe detectors for the Kety-Schmidt technique were embedded in a shielded brass block to minimize interference with radiation from the animal's body. 133Xe clearance data were analyzed using stochastic (CBF10, CBF15, and CBFINF) and initial slope methods (CBFIS), and the results were compared with CBFKS using linear regression. CBF15 and CBFINF yielded similar CBF values as CBFKS (CBFKS = 0.97.CBF15-2.08, r = 0.92, p less than 0.01; CBFKS = 1.13.CBFINF-1.21, r = 0.92, p less than 0.01). CBF10 slightly overestimated CBFKS but still showed a close correlation to CBFKS (CBFKS = 0.89.CBF10-2.58, r = 0.92, p less than 0.01) and CBFIS considerably overestimated CBFKS (CBFKS = 0.60.CBFIS-1.27, r = 0.87, p less than 0.01). With extracranial contamination of the 133Xe clearance curve minimized, all 133Xe clearance techniques used to measure CBF were consistently related to CBFKS in a constant, significant manner. 133Xe clearance therefore is a valid method to assess CBF during cardiopulmonary bypass.

Influence of anesthesia on the threshold of pacing-induced ischemia

Increased myocardial oxygen demand, induced by increased heart rate, may cause myocardial ischemia in the presence of significant coronary artery disease. Alterations in anesthetic depth or technique might put at risk or protect myocardium with compromised blood flow. In 20 dogs with critical left anterior descending coronary artery (LAD) stenosis, atrial pacing rates from 100 to 160 beats/min were achieved, with end-tidal halothane 0.7% (LowH) and 1.1% (HighH), end-tidal isoflurane 1.1% (LowI) and 1.5% (HighI), as well as with continuous fentanyl plus midazolam (FM) infusion anesthesia. Despite significantly different mean arterial and coronary perfusion pressures, rate-pressure product, and left ventricular dP/dtmax, the pacing rate at which systolic shortening decreased below the lower limit of the physiologic response, indicating regional dysfunction, was the same in all investigated anesthesia conditions (LowH: 127 +/- 4 beats/min; HighH: 128 +/- 5 beats/min; LowI: 125 +/- 4 beats/min; HighI: 122 +/- 5 beats/min; FM: 124 +/- 4 beats/min [mean +/- SEM], P greater than 0.05). None of the investigated anesthesia conditions either increased ischemia tolerance or showed a detrimental effect on myocardium with compromised coronary blood flow.

Effects of cardiopulmonary bypass and cardioplegia on regional and global cardiac actions of halothane in dogs

Cardiopulmonary bypass (CPB) with aortic cross-clamping represents a controlled period of global cardiac ischemia. We hypothesized that CPB (asanguineous prime), with aortic cross-clamping and repeated cardioplegia, alters myocardial function, which would be manifested as an exaggerated myocardial depression caused by halothane after CPB. In nine dogs anesthetized with fentanyl and midazolam, halothane dose-response curves (0.0%-2.0%) were compared before and after CPB. A reduced mean arterial blood pressure (46.4 +/- 3.7 vs 85.8 +/- 5.9 mm Hg), associated with a marked hemodilution (hematocrit, 19% +/- 1% vs 41% +/- 2%), was observed after CPB. Cardiac output and systolic shortening were not significantly different after versus before CPB during fentanyl-midazolam anesthesia. Normalized to fentanyl-midazolam hemodynamics, halothane dose-response curves before and after CPB were identical for all variables except cardiac output, where halothane caused a slight but statistically significantly more pronounced decrease after CPB compared with before CPB. The effect of halothane on left ventricular function, therefore, is relatively unaffected by CPB with cardioplegia.