Predicting Breast Cancer Subtypes Using Magnetic Resonance Imaging Based Radiomics With Automatic Segmentation.

OBJECTIVE: The aim of the study is to demonstrate whether radiomics based on an automatic segmentation method is feasible for predicting molecular subtypes. METHODS: This retrospective study included 516 patients with confirmed breast cancer. An automatic segmentation-3-dimensional UNet-based Convolutional Neural Networks, trained on our in-house data set-was applied to segment the regions of interest. A set of 1316 radiomics features per region of interest was extracted. Eighteen cross-combination radiomics methods-with 6 feature selection methods and 3 classifiers-were used for model selection. Model classification performance was assessed using the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity. RESULTS: The average dice similarity coefficient value of the automatic segmentation was 0.89. The radiomics models were predictive of 4 molecular subtypes with the best average: AUC = 0.8623, accuracy = 0.6596, sensitivity = 0.6383, and specificity = 0.8775. For luminal versus nonluminal subtypes, AUC = 0.8788 (95% confidence interval [CI], 0.8505-0.9071), accuracy = 0.7756, sensitivity = 0.7973, and specificity = 0.7466. For human epidermal growth factor receptor 2 (HER2)-enriched versus non-HER2-enriched subtypes, AUC = 0.8676 (95% CI, 0.8370-0.8982), accuracy = 0.7737, sensitivity = 0.8859, and specificity = 0.7283. For triple-negative breast cancer versus non-triple-negative breast cancer subtypes, AUC = 0.9335 (95% CI, 0.9027-0.9643), accuracy = 0.9110, sensitivity = 0.4444, and specificity = 0.9865. CONCLUSIONS: Radiomics based on automatic segmentation of magnetic resonance imaging can predict breast cancer of 4 molecular subtypes noninvasively and is potentially applicable in large samples.

PPARγ Activation-Mediated Egr-1 Inhibition Benefits Against Brain Injury in an Experimental Ischaemic Stroke Model.

BACKGROUND: Inflammatory response is a critical contributor to cerebral ischaemia injuries and blood-brain barrier (BBB) dysfunction. Early growth response-1 (Egr-1), an oxygen-sensing transcription factor which is rapidly and markedly triggered in ischaemic events, acts as a master switch coordinating the upregulation of multiple target proinflammatory genes. Here, we explored whether peroxisome proliferator-activated receptor-gamma (PPARγ) activation by telmisartan can modulate Egr-1 expression and the subsequent inflammatory responses in a rat model of cerebral ischaemia. METHODS: Cerebral ischaemia was induced in rats by middle cerebral artery occlusion (MCAO). Brain injury was evaluated by brain water content, infarct volume, and Evans blue dye extravasation. Egr-1 and claudin-5 levels were assessed by western blot and real-time polymerase chain reaction. RESULTS: MCAO-provoked Egr-1 expression was time dependent, peaking at 24 h and continuing to 72 h. The elevation in Egr-1 was coupled with a reduction in claudin-5. Telmisartan treatment significantly corrected the alterations of Egr-1 and claudin-5, alleviated the neurological deficits, and reduced brain water content, infarct volume, and Evans blue dye extravasation 24 h after MCAO. However, all the benefits of telmisartan were reversed by antagonising PPARγ with GW9662. CONCLUSION: Egr-1, a proinflammatory factor, is positively associated with post-ischaemic inflammation and the associated BBB dysfunction. PPARγ serves as an upstream transcription factor of the Egr-1 cascade. Targeting Egr-1 may emerge as a potential strategy to suppress inflammatory responses following ischaemic stroke.

Serum high-density lipoprotein cholesterol levels predict early recurrence and prognosis of intrahepatic cholangiocarcinoma after surgical resection.

Introduction: Dysregulation in lipid metabolism contributes to the occurrence and development of various cancers. The connection between changes in lipid metabolism and the development of intrahepatic cholangiocarcinoma remains uncertain. Our objective was to investigate the significance of blood lipid levels in patients with intrahepatic cholangiocarcinoma who have undergone surgery. Methods: Ninety-seven ICC patients who underwent surgery were retrospectively enrolled. After 92.2 months of follow-up, the Kaplan-Meier analysis and Cox proportional hazard model were used to calculate overall survival and recurrence-free survival. Results: The median age of this cohort was 56 years, and 79 (81.4 %) of them were male. Eighty-eight (90.7 %) patients presented with tumor recurrence and 73 (75.3 %) died. In multivariate analyses, high-density lipoprotein cholesterol level (<0.91 vs. ≥ 0.91 mmol/L, hazard ratio [HR] = 2.55; 95 % CI: 1.38-4.71), lymph node metastasis (Yes vs. No, HR = 2.58; 95 % CI: 1.28-5.19), etiology factor (chronic HBV infection vs. others, HR = 0.5; 95 % CI: 0.28-0.88) and multiple tumor lesions (Yes vs. No, HR = 1.85; 95 % CI: 1.01-3.39) were independent predictors of overall survival. However, only high-density lipoprotein cholesterol level (HR = 1.86; 95 % CI: 1.19-2.92) emerged as the independent factor for recurrence-free survival. High-density lipoprotein cholesterol level (HR = 2.07; 95 % CI: 1.26-3.41), etiology factor (HR = 0.49; 95 % CI: 0.29-0.84), and multiple tumor lesions (HR = 2.00; 95 % CI: 1.14-3.51) were independent predictors of early recurrence. For patients who did not experience the spread of cancer to the lymph nodes, there was a significant correlation between the level of high-density lipoprotein cholesterol and their overall survival, recurrence-free survival, and early recurrence. For patients with low pre-operation high-density lipoprotein cholesterol levels, high post-operation high-density lipoprotein cholesterol levels were associated with better prognosis. Conclusions: Low serum high-density lipoprotein cholesterol level might serve as a sign of poor clinical outcomes (overall survival and recurrence-free survival) and early recurrence among intrahepatic cholangiocarcinoma patients. Strengthening the monitoring and intervention of intrahepatic cholangiocarcinoma patients with poor prognosis might be critical for improving the prognosis.

Association of the rs3077 and rs9277535 polymorphisms in HLA-DP with hepatitis B virus infection and spontaneous clearance: a meta-analysis.

PURPOSE: Owing to inconsistent observations in the literature of an association between HLA-DP polymorphisms (rs3077 and rs9277535) and hepatitis B virus (HBV) infection and spontaneous clearance, there is an urgent need for a comprehensive and reliable understanding of this subject. This meta-analysis was performed to quantitatively summarise the evidence for the relevance of these HLA-DP polymorphisms to HBV infection and spontaneous clearance. METHODS: A meta-analysis was conducted with the data from eight relevant papers published from April 2009 to March 2012, following strict selection. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for alleles, co-dominant, dominant and recessive genotype models of the rs3077 and rs9277535 loci. RESULTS: Our analysis indicated a significant association of rs3077 and rs9277535 in HLA-DP with HBV infection, suggesting that these HLA-DP polymorphisms act beneficially against HBV infection (for rs3077, AG vs. GG: OR = 0.522, 95% CI = 0.485-0.561; AA vs. GG: OR = 0.350, 95% CI = 0.311-0.393; for rs9277535, AG vs. GG: OR = 0.542, 95% CI = 0.506-0.579; AA vs. GG: OR = 0.371, 95% CI = 0.336-0.409). Additionally, these HLA-DP polymorphisms served as protective factors in the spontaneous clearance of HBV (for rs3077, AG vs. GG: OR = 0.600, 95% CI = 0.464-0.775; AA vs. GG: OR = 0.420, 95% CI = 0.299-0.590; for rs9277535, AG vs. GG: OR = 0.623, 95% CI = 0.570-0.681 and AA vs. GG: OR = 0.464, 95% CI = 0.386-0.556) with similar results for both dominant and recessive genotype models. CONCLUSIONS: Our results demonstrated that the rs3077 and rs9277535 HLA-DP polymorphisms reduced HBV infection and increased the likelihood of spontaneous viral clearance in some Asian populations.

[A clinical and pathological analysis of 22 cases of primary sclerosing cholangitis].

OBJECTIVE: To characterize the clinical, laboratory, imaging and pathological features of primary sclerosing cholangitis (PSC) and investigate the impact of ursodeoxycholic acid (UDCA) therapy on patient prognosis. METHODS: The medical records of 22 patients diagnosed with PSC between 2002 and 2011 were retrospectively reviewed. The PSC diagnosis had been made in patients with suspect biochemical abnormalities following evaluation by magnetic resonance cholangiopancreatography (MRCP) and/or endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC). Fibrosis and inflammation were assessed by immunohistochemical analyses of tissue biopsies. Outcome of patients treated with UDCA (13-15 mg/kg/day, oral) were compared to that of patients without UDCA treatment by the X2 or corrected X2 tests. RESULTS: Among the 22 PSC patients, the majority was male (n=15) and presented with fatigue, dark urine, and body weight loss (n=15). Four cases had ulcerative colitis. At admission, all 22 cases showed elevated levels of alkaline phosphatase[ALP: (348+/-184) U/L], 19 cases showed elevated alanine aminotransferase [ALT: (94.0+/-67.0) U/L] and aspartate aminotransferase [AST: (98.0+/-67.0) U/L], and 15 cases showed elevated levels of total bilirubin (99.0+/-115.0) mumol/L and direct bilirubin (74.4+/-92.4 mumol/L. ERCP examination showed segmental intrahepatic bile duct stenosis with expansion, and stiff and enlarged gallbladder bile ducts, but unclear findings for the common bile ducts and pancreatic ducts. MRCP showed beading of the intrahepatic bile duct, stiffness of the bile duct wall, and dilation of the common bile duct. Fibrosis and inflammation were observed in the bile ducts, along with hyperplasia and the typical features of "onion skin" fibrosis and fibrous obliterative cholangitis. Five of the 10 patients treated with UDCA improved, and seven of the 12 patients in the non-UDCA treatment group improved. There was no statistically significant difference in outcome between the groups (paired X2=0.333, corrected X2=0.083, P more than 0.05). CONCLUSION: PSC patients were predominantly male and the common clinical manifestations were fatigue, dark urine, and body weight loss. At admission, serum biochemical indicators of cholangitis were increased significantly and subsequent imaging studies confirmed the suspected diagnosis by showing obvious characteristic changes. UDCA treatment did not significantly improve patient prognosis.

Computed tomography-based COVID-19 triage through a deep neural network using mask-weighted global average pooling.

Background: There is an urgent need to find an effective and accurate method for triaging coronavirus disease 2019 (COVID-19) patients from millions or billions of people. Therefore, this study aimed to develop a novel deep-learning approach for COVID-19 triage based on chest computed tomography (CT) images, including normal, pneumonia, and COVID-19 cases. Methods: A total of 2,809 chest CT scans (1,105 COVID-19, 854 normal, and 850 non-3COVID-19 pneumonia cases) were acquired for this study and classified into the training set (n = 2,329) and test set (n = 480). A U-net-based convolutional neural network was used for lung segmentation, and a mask-weighted global average pooling (GAP) method was proposed for the deep neural network to improve the performance of COVID-19 classification between COVID-19 and normal or common pneumonia cases. Results: The results for lung segmentation reached a dice value of 96.5% on 30 independent CT scans. The performance of the mask-weighted GAP method achieved the COVID-19 triage with a sensitivity of 96.5% and specificity of 87.8% using the testing dataset. The mask-weighted GAP method demonstrated 0.9% and 2% improvements in sensitivity and specificity, respectively, compared with the normal GAP. In addition, fusion images between the CT images and the highlighted area from the deep learning model using the Grad-CAM method, indicating the lesion region detected using the deep learning method, were drawn and could also be confirmed by radiologists. Conclusions: This study proposed a mask-weighted GAP-based deep learning method and obtained promising results for COVID-19 triage based on chest CT images. Furthermore, it can be considered a convenient tool to assist doctors in diagnosing COVID-19.

Preliminary adipose removal did not prevent diet-induced metabolic disorders in mice.

BACKGROUND: Obesity is a fundamental factor in metabolic disorders such as hyperlipidemia, insulin resistance, fatty liver, and atherosclerosis. However, effective preventive measures are still lacking. This study aimed to investigate different surgical protocols for removing partial adipose tissue before the onset of obesity and determine whether, and by which protocol, preliminary adipose removal could exert potent preventive effects against diet-induced metabolic disorders. METHODS: Male low-density lipoprotein receptor (LDL-R) knockout (KO) mice were randomly divided into four groups and subjected to epididymal fat removal (Epi-FR) surgery, subcutaneous fat removal (suQ-FR) surgery, both subcutaneous and epididymal fat removal (Epi + suQ-FR) surgery, or sham-operation. After 1 week of recovery, all mice were given a high-fat diet (HFD) for 10 weeks to induce metabolic disorders. RESULTS: In the Epi-FR group and the sham-operated group, the mean numbers of the residual subcutaneous fat were 28.59 mg/g and 18.56 mg/g, respectively. The expression of relative genes such as Pparg, Cebpa, Dgat2, Fabp4 and Cd36 in the residual subcutaneous fat increased 2.62, 3.90, 3.11, 2.06, 1.78 times in the Epi-FR group compared with that in the sham-operated group. Whereas in the other fat-removal groups, the residual fat depots had no significant change in either size or gene expression, as compared with those of the sham-operated group. Plasma lipid and glucose levels and insulin sensitivity, as detected by the glucose tolerance test, were not significantly alleviated in the three fat removal groups. Liver mass or lipid content was not attenuated in any of the three fat removal groups. The atherosclerosis burdens in the entire inner aorta and aortic root did not decrease in any of the three fat removal groups. CONCLUSIONS: Our data suggest that removal of epididymal adipose or subcutaneous adipose alone or in combination before the onset of obesity did not protect against hyperlipidemia, insulin resistance, fatty liver, or atherosclerosis in LDL-R KO mice fed with a HFD. Hence, adipose removal possibly does not represent a potential approach in preventing obesity-related metabolic disorders in the obesity-susceptible population.

Outbreak of Mycoplasma pneumoniae at a military academy.

In 2019, an outbreak of Mycoplasma pneumoniae occurred at a military academy in China. The attack rate (10.08%,60/595) was significantly different among the units. High-intensity training and crowded environments to which cadets are exposed are the high risk factors for the outbreak of M. pneumoniae. In-time prevention and control measures effectively controlled the spread of the epidemic.

Clinical and computed tomographic imaging features of novel coronavirus pneumonia caused by SARS-CoV-2.

PURPOSE: To investigate the clinical and imaging characteristics of computed tomography (CT) in novel coronavirus pneumonia (NCP) caused by SARS-CoV-2. MATERIALS AND METHODS: A retrospective analysis was performed on the imaging findings of patients confirmed with COVID-19 pneumonia who had chest CT scanning and treatment after disease onset. The clinical and imaging data were analyzed. RESULTS: Fifty patients were enrolled, including mild type in nine, common in 28, severe in 10 and critically severe in the rest three. Mild patients (29 years) were significantly (P<0.03) younger than either common (44.5 years) or severe (54.7) and critically severe (65.7 years) patients, and common patients were also significantly (P<0.03) younger than severe and critically severe patients. Mild patients had low to moderate fever (<39.1 °C), 49 (98%) patients had normal or slightly reduced leukocyte count, 14 (28%) had decreased counts of lymphocytes, and 26 (52%) patients had increased C-reactive protein. Nine mild patients were negative in CT imaging. For all the other types of NCP, the lesion was in the right upper lobe in 30 cases, right middle lobe in 22, right lower lobe in 39, left upper lobe in 33 and left lower lobe in 36. The lesion was primarily located in the peripheral area under the pleura with possible extension towards the pulmonary hilum. Symmetrical lesions were seen in 26 cases and asymmetrical in 15. The density of lesion was mostly uneven with ground glass opacity as the primary presentation accompanied by partial consolidation and fibrosis. CONCLUSION: CT imaging presentations of NCP are mostly patchy ground glass opacities in the peripheral areas under the pleura with partial consolidation which will be absorbed with formation of fibrotic stripes if improved. CT scanning provides important bases for early diagnosis and treatment of NCP.

Persistent Viral Presence Determines the Clinical Course of the Disease in COVID-19.

BACKGROUND: The clinical management of coronavirus disease 2019 (COVID-19) is dependent on understanding the underlying factors that contribute to the disease severity. In the absence of effective antiviral therapies, other host immunomodulatory therapies such as targeting inflammatory response are currently being used without clear evidence of their effectiveness. Because inflammation is an essential component of host antiviral mechanisms, therapies targeting inflammation may adversely affect viral clearance and disease outcome. OBJECTIVE: To understand whether the persistent presence of the virus is a key determinant in the disease severity during COVID-19 and to determine whether the viral reactivation in some patients is associated with infectious viral particles. METHODS: The data for patients were available including the onset of the disease, duration of viral persistence, measurements of inflammatory markers such as IL-6 and C-reactive protein, chest imaging, disease symptoms, and their durations among others. Follow-up tests were performed to determine whether the viral negative status persists after their recovery. RESULTS: Our data show that patients with persistent viral presence (>16 days) have more severe disease outcomes including extensive lung involvement and requirement of respiratory support. Two patients who died of COVID-19 were virus-positive at the time of their death. Four patients demonstrated virus-positive status on the follow-up tests, and these patient samples were sent to viral culture facility where virus culture could not be established. CONCLUSIONS: These data suggest that viral persistence is the key determining factor of the disease severity. Therapies that may impair the viral clearance may impair the host recovery from COVID-19.

Exploring an Integrative Therapy for Treating COVID-19: A Randomized Controlled Trial.

OBJECTIVES: To develop a new Chinese medicine (CM)-based drug and to evaluate its safety and effect for suppressing acute respiratory distress syndrome (ARDS) in COVID-19 patients. METHODS: A putative ARDS-suppressing drug Keguan-1 was first developed and then evaluated by a randomized, controlled two-arm trial. The two arms of the trial consist of a control therapy (alpha interferon inhalation, 50 µg twice daily; and lopinavir/ritonavir, 400 and 100 mg twice daily, respectively) and a testing therapy (control therapy plus Keguan-1 19.4 g twice daily) by random number table at 1:1 ratio with 24 cases each group. After 2-week treatment, adverse events, time to fever resolution, ARDS development, and lung injury on newly diagnosed COVID-19 patients were assessed. RESULTS: An analysis of the data from the first 30 participants showed that the control arm and the testing arm did not exhibit any significant differences in terms of adverse events. Based on this result, the study was expanded to include a total of 48 participants (24 cases each arm). The results show that compared with the control arm, the testing arm exhibited a significant improvement in time to fever resolution (P=0.035), and a significant reduction in the development of ARDS (P=0.048). CONCLUSIONS: Keguan-1-based integrative therapy was safe and superior to the standard therapy in suppressing the development of ARDS in COVID-19 patients. (Trial registration No. NCT04251871 at www.clinicaltrials.gov ).

Synaptic islands defined by the territory of a single astrocyte.

In the mammalian brain, astrocytes modulate neuronal function, in part, by synchronizing neuronal firing and coordinating synaptic networks. Little, however, is known about how this is accomplished from a structural standpoint. To investigate the structural basis of astrocyte-mediated neuronal synchrony and synaptic coordination, the three-dimensional relationships between cortical astrocytes and neurons was investigated. Using a transgenic and viral approach to label astrocytes with enhanced green fluorescent protein, we performed a three-dimensional reconstruction of astrocytes from tissue sections or live animals in vivo. We found that cortical astrocytes occupy nonoverlapping territories similar to those described in the hippocampus. Using immunofluorescence labeling of neuronal somata, a single astrocyte enwraps on average four neuronal somata with an upper limit of eight. Single-neuron dye-fills allowed us to estimate that one astrocyte contacts 300-600 neuronal dendrites. Together with the recent findings showing that glial Ca2+ signaling is restricted to individual astrocytes in vivo, and that Ca2+ signaling leads to gliotransmission, we propose the concept of functional islands of synapses in which groups of synapses confined within the boundaries of an individual astrocyte are modulated by the gliotransmitter environment controlled by that astrocyte. Our description offers a new structurally based conceptual framework to evaluate functional data involving interactions between neurons and astrocytes in the mammalian brain.

Hydrogen sulfide improves endothelial dysfunction in hypertension by activating peroxisome proliferator-activated receptor delta/endothelial nitric oxide synthase signaling.

OBJECTIVE: We aimed to elucidate the ameliorative effect of hydrogen sulfide (H2S) on endothelium-dependent relaxation disturbances via peroxisome proliferator-activated receptor delta/endothelial nitric oxide synthase (PPARδ/eNOS) pathway activation in hypertensive patients and rats. METHODS: Renal arteries were collected from normotensive and hypertensive patients who underwent nephron-sparing surgery. Renal arteries from 37 patients were cultured with or without sodium H2S (NaHS) 50 µmol/l. The rats were randomly divided into four groups: Sham; Sham + NaHS, two kidneys; one clipped (2K1C); and 2K1C + NaHS. Mean arterial pressure was measured by tail-cuff plethysmography. A microvessel recording technique was used to observe the effect of NaHS on endothelium-dependent relaxation. Plasma H2S concentrations were detected using the monobromobimane method. Real-time PCR and western blotting were used to assess mRNA and protein levels of AT1, cystathionine γ-lyase, PPARδ, and phosphor-eNOS. Laser confocal scanning microscopy measured intracellular NO production in human umbilical vein endothelial cells. RESULTS: NaHS improved endothelial function in hypertensive humans and rats. The 20-week administration of NaHS to 2K1C rats lowered the mean arterial pressure. In human umbilical vein endothelial cells, NaHS improved the AngII-induced production of NO. NaHS upregulated PPARδ expression, increased protein kinase B (Akt) or adenosine monophosphate kinase-activated protein kinase (AMPK) phosphorylation, and enhanced eNOS phosphorylation. A PPARδ agonist could mimic the ameliorative effect of NaHS that was suppressed by PPARδ, AMPK, or Akt inhibition. CONCLUSION: H2S plays a protective function in renal arterial endothelium in hypertension by activating the PPARδ/PI3K/Akt/eNOS or PPARδ/AMPK/eNOS pathway. H2S may serve as an effective strategy against hypertension.

Hydrogen Sulfide Improves Endothelial Dysfunction via Downregulating BMP4/COX-2 Pathway in Rats with Hypertension.

Aims. We object to elucidate that protective effect of H2S on endothelium is mediated by downregulating BMP4 (bone morphogenetic protein 4)/cyclooxygenase- (COX-) 2 pathway in rats with hypertension. Methods and Results. The hypertensive rat model induced by two-kidney one-clip (2K1C) model was used. Exogenous NaHS administration (56 µmol/kg/day, intraperitoneally once a day) reduced mean arterial pressure (MAP) of 2K1C rats from 199.9 ± 3.312 mmHg to 159.4 ± 5.434 mmHg, while NaHS did not affect the blood pressure in the Sham rats and ameliorated endothelium-dependent contractions (EDCs) of renal artery in 2K1C rats. 2K1C reduced CSE level twofold, decreased plasma levels of H2S about 6-fold, increased BMP4, Nox2, and Nox4 levels 2-fold and increased markers of oxidative stress MDA and nitrotyrosine 1.5-fold, upregulated the expression of phosphorylation-p38 MAPK 2-fold, and increased protein levels of COX-2 1.5-fold, which were abolished by NaHS treatment. Conclusions. Our results demonstrate that H2S prevents activation of BMP4/COX-2 pathway in hypertension, which may be involved in the ameliorative effect of H2S on endothelial impairment. These results throw light on endothelial protective effect of H2S and provide new target for prevention and therapy of hypertension.

Expression of thymosin beta4 mRNA by activated microglia in the denervated hippocampus.

Thymosin beta4 is a major actin-sequestering molecule. Here, we report a prominent upregulation of thymosin beta4 in the hippocampus following entorhinal deafferentation. Northern blotting displayed a transient increase of thymosin beta4 mRNA in the deafferented hippocampus by 1.8, 2.3, 1.3 and 1.1-fold of controls, respectively, at 1, 3, 7 and 15 days post-lesion. In-situ hybridization confirmed that the induction of thymosin beta4 mRNA specifically occurred in the entorhinally denervated zones of the hippocampus. The double labeling of in-situ hybridization for thymosin beta4 mRNA with isolectin B4 cytochemistry showed that isolectin B4-positive microglial cells are responsible for deafferentation-induced thymosin beta4 mRNA expression. The results suggest that thymosin beta4 may participate in the process of microglial activation, which is the earliest event in lesion-induced plasticity.

[Limb ischemic preconditioning reduces infarct size following myocardial ischemia-reperfusion in rats].

The effect of limb ischemic preconditioning (LIP) on ischemia-reperfused myocardium was examined in the urethane-anesthetized rats to determine whether LIP produces cardioprotection and to observe the roles of adenosine and neural reflex in this effect. The area at risk (AR) and infarct area (IA) were determined using Evans blue and nitro-blue tetrazolium staining respectively. Infarct size (IS) was defined as 100xIA/AR (%). The results obtained are as follows: (1) During 30 min myocardial ischemia and subsequent 120 min reperfusion, the myocardial infarct size occupied 51.48+/-0.82% of the area at risk. (2) LIP significantly reduced the myocardial infarct size to 35.14+/-0.88% (p<0.01 ), indicating the cardioprotective effect of such an intervention. (3) Femoral nerve section (FNS) completely abolished the cardioprotection afforded by LIP. (4) Intrafemoral artery injection of adenosine (10 nmol/kg) produced a similar effect to that of LIP, reducing the myocardial infarct size to 37.28+/-1.68%, while intrafemoral vein injection of the same dose of adenosine showed no effect. (5) Pretreatment with a selective adenosine A(1) receptor antagonist 8-cyclopentyl-1,diproylxanthine (DPCPX ) (32 nmol/kg) partially abolished the cardioprotection of LIP on myocardium. Taken together, it is concluded that LIP reduces infarct size following myocardial ischemia-reperfusion, and that the locally released adenosine and thereby the activated relevant neural pathway play an important role in the cardioprotection provided by LIP.

Electrophysiological effects of resveratrol on guinea pig papillary muscles.

The purpose of this study was to investigate the electrophysiological effects of resveratrol on guinea pig papillary muscles and the underlying mechanism. Action potentials were recorded by using intracellular microelectrode technique. The results obtained are as follows: (1) In normal papillary muscles, resveratrol (30, 60, and 120 micromol/L) shortened the duration of action potential (APD) in a concentration-dependent manner. (2) In partially depolarized papillary muscles, resveratrol (60 micromol/L ) not only shortened APD, but also decreased the amplitude of action potential (APA), overshoot (OS) and maximal rate of depolarization in phase 0 (Vmax). (3) Perfusion with Ca2+-free K-H solution, completely abolished the effects of resveratrol (60 micromol/L) on papillary muscles. (4) Application of potassium channel blocker tetraethylammonium chloride (TEA, 20 mmol/L) did not prevent the effect of resveratrol (60 micromol/L) on action potential. (5) Pretreatment with NG-nitro-L-arginine methyl ester (L-NAME, 1 mmol/L), a nitric oxide (NO) synthase inhibitor, failed to abolish the effect of resveratrol (60 micromol/L). All these results indicate that the electrophysiological effects of resveratrol on guinea pig papillary muscles are likely due to the reduction of calcium influx, which might not be mediated by NO.

High-frequency electrical stimulation of femoral nerve reduces infarct size following myocardial ischemia-reperfusion in rats.

The effects of femoral nerve electrostimulation (FNES) on ischemia-reperfused myocardium were examined in the urethane- anesthetized rats to determine whether FNES may provide cardioprotection and to observe the possible mechanism. The area at risk (AR) and infarct area (IA) were determined using Evans blue and nitro-blue tetrazolium staining, respectively. Infarct size (IS) was defined as 100xIA/AR (%). The results are as follows: (1) During 30 min myocardial ischemia and subsequent 120 min reperfusion, the myocardial infarct size occupied (54.96+/-0.82)% of the area at risk. (2) FNES of high frequency (10 V, 100 Hz, 1 ms) significantly reduced myocardial infarct size to (36.94+/-1.34)% (P<0.01), indicating the cardioprotective effect FNES of high frequency on myocardial ischemia-reperfusion, while FNES of low frequency (10 V, 10 Hz, 1 ms) had no effect on myocardial infarct size. (3) Pretreatment with either naloxone (5 mg /kg, i.v), a nonselective opioid receptor antagonist, or glibenclamide (5 mg /kg, i.v), a K(ATP) channel antagonist, completely abolished the cardioprotection of FNES (100 Hz) from myocardial ischemia-reperfusion. It is suggested that FNES of high frequency can protect myocardium from ischemia-reperfusion injury. The possible mechanism is that FNES of high frequency may induce the release of opioids from the central nervous system, and the activation of opioid receptors in the heart results in an opening of myocardial K(ATP) channels which can protect myocardium.

Lesion-induced gelsolin upregulation in the hippocampus following entorhinal deafferentation.

Gelsolin is an actin-binding protein that regulates actin filament-severing and capping activity in the various processes of cell motilities. Here, we report the expression of gelsolin mRNA and protein in the hippocampus following transections of the entorhinal afferents. Northern blot analysis showed that transcript of gelsolin was upregulated in a transient manner in the deafferented hippocampus by 1.3-, 2.1-, 1.7-, and 1.1- folds of controls, respectively, at 1, 3, 7, and 15 days postlesion (dpl). In situ hybridization and immunohistochemistry confirmed the temporal expression of gelsolin specifically in the entorhinally denervated zones: the stratum lacunosum-molecular (SLM) of the hippocampus and the outer molecular layer (OML) of the dentate gyrus (DG), which initiated as early as at 1 dpl, reached the maximum at 3 dpl, remained prominently elevated by 7 dpl, and discernibly higher at 15 dpl than that of controls. Double labeling of either gelsolin mRNA or protein with markers of glial cells (Griffonia simplicifolia IB4 and CD11b for microglial cells, GFAP for astroglial cells) revealed that gelsolin was highly expressed by both activated microglia and astrocytes. The results suggest that the spatiotemporal upregulation of gelsolin in the hippocampus is induced by entorhinal deafferentation, and that gelsolin would participate in the activation processes of both microglial and astroglial cells and thereby, indirectly play important roles in the subsequent lesion-induced neural reorganization in the hippocampus following entorhinal deafferentation.

Induction of ephrin-B1 and EphB receptors during denervation-induced plasticity in the adult mouse hippocampus.

Abstract It has been widely demonstrated that Eph receptors and their ephrin ligands play multiple pivotal roles in the development of the nervous system. However, less is known about their roles in the adult brain. Here we reported the expression of ephrin-B1 and its cognate EphB receptors in the adult mouse hippocampus at 3, 7, 15, 30 and 60 days after transections of the entorhinal afferents. In situ hybridization and immunohistochemistry showed the time-dependent up-regulation of ephrin-B1 in the denervated areas of the hippocampus, which initiated at 3 days postlesion (dpl), reached maximal levels at 7-15 dpl, remained slightly elevated at 30 dpl and recovered to normal levels by 60 dpl. Double labeling of ephrin-B1 and glial fibrillary acidic protein revealed that ephrin-B1-expressing cells in the denervated areas were reactive astrocytes. Furthermore, a ligand-binding assay using ephrin-B1/Fc chimera protein also displayed the up-regulation of EphB receptors in the denervated areas of the hippocampus in a similar manner to that of ephrin-B1. Within the first week postlesion, the EphB receptors were expressed by reactive astrocytes. After 7 dpl, however, EphB receptors were expressed not only by reactive astrocytes but also first by sprouting axons and later by regrowing dendrites. These results suggest that the ephrin-B1/EphB system may participate in the lesion-induced plasticity processes in the adult mouse hippocampus.