Oral mirtazapine decreases the gastrointestinal adverse effects in cats on doxorubicin chemotherapy

Anorexia, depression, and vomiting are the common adverse effects of chemotherapy in humans and animals. Mirtazapine is primarily used as an appetite stimulant and antiemetic in dogs and cats. Therefore, we evaluated the efficacy of mirtazapine in reducing the gastrointestinal adverse effects in cats receiving doxorubicin chemotherapy. This single-masked, placebo-controlled crossover study enrolled 11 cats with malignant mammary gland tumors. The cats were randomly assigned to receive either mirtazapine (1.88 mg/cat) or placebo every 48 h for 2 weeks from the first initiation of doxorubicin chemotherapy. Each cat was then crossed over to the alternate group on the subsequent chemotherapy with a 1-week wash-out period. The owners were asked to record appetite score, activity score, episodes of vomiting and diarrhea for 2 weeks after each doxorubicin administration. Cats treated with mirtazapine showed significantly increased bodyweight compared with those on placebo (P = 0.010). The appetite and activity scores during mirtazapine treatment was significantly higher than those during placebo treatment (P = 0.005 and 0.018, respectively). Furthermore, the prevalence of episodes of vomiting during mirtazapine treatment was significantly lower than that during placebo treatment (P = 0.026). Our results demonstrate that mirtazapine can significantly increase bodyweight, appetite, and activity and reduce vomiting in cats after doxorubicin chemotherapy.

Peptide-mediated targeted delivery of SOX9 nanoparticles into astrocytes ameliorates ischemic brain injury

Astrocytes are highly activated following brain injuries, and their activation influences neuronal survival. Additionally, SOX9 expression is known to increase in reactive astrocytes. However, the role of SOX9 in activated astrocytes following ischemic brain damage has not been clearly elucidated yet. Therefore, in the present study, we investigated the role of SOX9 in reactive astrocytes using a poly-lactic-co-glycolic acid (PLGA) nanoparticle plasmid delivery system in a photothrombotic stroke animal model. We designed PLGA nanoparticles to exclusively enhance SOX9 gene expression in glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes. Our observations indicate that PLGA nanoparticles encapsulated with GFAP:SOX9:tdTOM reduce ischemia-induced neurological deficits and infarct volume through the prostaglandin D2 pathway. Thus, the astrocyte-targeting PLGA nanoparticle plasmid delivery system provides a potential opportunity for stroke treatment. Since the only effective treatment currently available is reinstating the blood supply, cell-specific gene therapy using PLGA nanoparticles will open a new therapeutic paradigm for brain injury patients in the future.

Kondo screening in a Majorana metal

Kondo impurities provide a nontrivial probe to unravel the character of the excitations of a quantum spin liquid. In the S = 1/2 Kitaev model on the honeycomb lattice, Kondo impurities embedded in the spin-liquid host can be screened by itinerant Majorana fermions via gauge-flux binding. Here, we report experimental signatures of metallic-like Kondo screening at intermediate temperatures in the Kitaev honeycomb material α-RuCl3 with dilute Cr3+ (S = 3/2) impurities. The static magnetic susceptibility, the muon Knight shift, and the muon spin-relaxation rate all feature logarithmic divergences, a hallmark of a metallic Kondo effect. Concurrently, the linear coefficient of the magnetic specific heat is large in the same temperature regime, indicating the presence of a host Majorana metal. This observation opens new avenues for exploring uncharted Kondo physics in insulating quantum magnets.

Development of metal radioactive liquid reference material for proficiency test

This study developed liquid reference materials containing various metals, to be used for quality assurance of radiation measurements of the most common metallic wastes generated during the operation or decommissioning of nuclear power plants. The liquid reference materials were prepared by assuming the dissolution of stainless-steel using acid and melting of the major metals present in the stainless steel, namely Fe, Ni, Cr, and Mn, along with the standard sources (134Cs, 137Cs, 60Co, 90Sr). The theoretical massic activity of the standard sources added to the samples and the measured reference values of the gamma and beta emitters in the samples were compared, and they showed good agreement within a one-sigma confidence interval (k = 1). Using the developed reference materials, a proficiency test was conducted on three domestic labs, and the results were evaluated using Z-score. While the evaluation results showed good agreement between the reference values and the reported values for 137Cs and 60Co, all participating labs reported lower values than the reference value for 134Cs. For 90Sr, two out of the three labs reported significantly higher values than the reference value. Based on the results of this study, the developed metal radioactive liquid reference material is expected to be registered as certified reference material (CRM) in the future. They will be used as the CRM for measuring and ensuring the quality of radioactive metal waste.

Aucubin Exerts Neuroprotection against Forebrain Ischemia and Reperfusion Injury in Gerbils through Antioxidative and Neurotrophic Effects

Aucubin is an iridoid glycoside that displays various pharmacological actions including antioxidant activity. However, there are few reports available on the neuroprotective effects of aucubin against ischemic brain injury. Thus, the aim of this study was to investigate whether aucubin protected against damage to hippocampal function induced by forebrain ischemia-reperfusion injury (fIRI) in gerbils, and to examine whether aucubin produced neuroprotection in the hippocampus against fIRI and to explore its mechanisms by histopathology, immunohistochemistry, and Western analysis. Gerbils were given intraperitoneal injections of aucubin at doses of 1, 5, and 10 mg/kg, respectively, once a day for seven days before fIRI. As assessed by the passive avoidance test, short-term memory function following fIRI significantly declined, whereas the decline in short-term memory function due to fIRI was ameliorated by pretreatment with 10 mg/kg, but not 1 or 5 mg/kg, of aucubin. Most of the pyramidal cells (principal cells) of the hippocampus died in the Cornu Ammonis 1 (CA1) area four days after fIRI. Treatment with 10 mg/kg, but not 1 or 5 mg/kg, of aucubin protected the pyramidal cells from IRI. The treatment with 10 mg/kg of aucubin significantly reduced IRI-induced superoxide anion production, oxidative DNA damage, and lipid peroxidation in the CA1 pyramidal cells. In addition, the aucubin treatment significantly increased the expressions of superoxide dismutases (SOD1 and SOD2) in the pyramidal cells before and after fIRI. Furthermore, the aucubin treatment significantly enhanced the protein expression levels of neurotrophic factors, such as brain-derived neurotrophic factor and insulin-like growth factor-I, in the hippocampal CA1 area before and after IRI. Collectively, in this experiment, pretreatment with aucubin protected CA1 pyramidal cells from forebrain IRI by attenuating oxidative stress and increasing neurotrophic factors. Thus, pretreatment with aucubin can be a promising candidate for preventing brain IRI.

Therapeutic Treatment with Pycnogenol® Attenuates Ischemic Brain Injury in Gerbils Focusing on Cognitive Impairment, Neuronal Death, BBB Leakage and Neuroinflammation in the Hippocampus

BACKGROUND

A gerbil model of ischemia and reperfusion (IR) injury in the forebrain has been developed for studies on mechanisms, prevention and therapeutic strategies of IR injury in the forebrain. Pycnogenol® (PYC), a standardized extract of French maritime pine tree (Pinus pinaster Aiton) has been exploited as an additive for dietary supplement. In the present study, we investigated the neuroprotective effects of post-treatment with PYC and its therapeutic mechanisms in gerbils.

METHODS

The gerbils were given sham and IR operation and intraperitoneally injected with vehicle and Pycnogenol® (25, 50 and 100 mg/kg, respectively) immediately, at 24 hours and 48 hours after sham and IR operation. Through 8-arm radial maze test and passive avoidance test, each spatial memory and short-term memory function was assessed. To examine the neuroprotection of Pycnogenol®, we conducted cresyl violet staining, immunohistochemistry for neuronal nuclei, and Fluoro-Jade B histofluorescence. Moreover, we carried out immunohistochemistry for immunoglobulin G (IgG) to investigate blood-brain barrier (BBB) leakage and interleukin-1β (IL-1β) to examine change in pro-inflammatory cytokine.

RESULTS

We found that IR-induced memory deficits were significantly ameliorated when 100 mg/kg Pycnogenol® was treated. In addition, treatment with 100 mg/kg Pycnogenol®, not 25 mg/kg nor 50 mg/kg, conferred neuroprotective effect against IR injury. For its mechanisms, we found that 100 mg/kg Pycnogenol® significantly reduced BBB leakage and inhibited the expression of IL-1β.

CONCLUSIONS

Therapeutic treatment (post-treatment) with Pycnogenol® after IR effectively attenuated ischemic brain injury in gerbils. Based on these results, we suggest that PYC can be employed as an important material for ischemic drugs.

Therapeutic Hypothermia after Cardiac Arrest Attenuates Hindlimb Paralysis and Damage of Spinal Motor Neurons and Astrocytes through Modulating Nrf2/HO-1 Signaling Pathway in Rats

Cardiac arrest (CA) and return of spontaneous circulation (ROSC), a global ischemia and reperfusion event, lead to neuronal damage and/or death in the spinal cord as well as the brain. Hypothermic therapy is reported to protect neurons from damage and improve hindlimb paralysis after resuscitation in a rat model of CA induced by asphyxia. In this study, we investigated roles of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in the lumbar spinal cord protected by therapeutic hypothermia in a rat model of asphyxial CA. Male Sprague-Dawley rats were subjected to seven minutes of asphyxial CA (induced by injection of 2 mg/kg vecuronium bromide) and hypothermia (four hours of cooling, 33 ± 0.5 °C). Survival rate, hindlimb motor function, histopathology, western blotting, and immunohistochemistry were examined at 12, 24, and 48 h after CA/ROSC. The rats of the CA/ROSC and hypothermia-treated groups had an increased survival rate and showed an attenuated hindlimb paralysis and a mild damage/death of motor neurons located in the anterior horn of the lumbar spinal cord compared with those of the CA/ROSC and normothermia-treated groups. In the CA/ROSC and hypothermia-treated groups, expressions of cytoplasmic and nuclear Nrf2 and HO-1 were significantly higher in the anterior horn compared with those of the CA/ROSC and normothermia-treated groups, showing that cytoplasmic and nuclear Nrf2 was expressed in both motor neurons and astrocytes. Moreover, in the CA/ROSC and hypothermia-treated group, interleukin-1β (IL-1β, a pro-inflammatory cytokine) expressed in the motor neurons was significantly reduced, and astrocyte damage was apparently attenuated compared with those found in the CA/ROSC and normothermia group. Taken together, our results indicate that hypothermic therapy after CA/ROSC attenuates CA-induced hindlimb paralysis by protecting motor neurons in the lumbar spinal cord via activating the Nrf2/HO-1 signaling pathway and attenuating pro-inflammation and astrocyte damage (reactive astrogliosis).

Association of left atrial ejection fraction and cardiovascular outcomes in Asian patients with hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National University of Singapore Yong Loo Lin School of Medicine's Junior Academic Fellowship Scheme

Background

The optimal method of risk stratification of hyp­ertrophic cardiomyopathy (HCM) patients, especially in the Asian population, is unknown. Left atrial ejection fraction (LAEF) is an emerging risk marker for cardiovascular outcomes. This study aimed to investigate whether LAEF was associated with cardiovascular outcomes in Asian patients with HCM.

Methods

This was a retrospective cohort study performed in a tertiary academic centre involving 291 consecutive patients diagnosed with HCM between 2010 and 2017. We collected the relevant clinical characteristics of these patients and retrospectively analysed the index transthoracic echocardiograms for novel left atrial indices including LAEF. We obtained the maximum (LAVmax) and minimum left atrial volumes (LAVmin) using the biplane method of disks in apical 4- and 2-chamber views. LAEF was derived by dividing the difference between LAVmax and LAVmin by LAVmax. We assessed the patients for outcomes of (1) heart failure requiring admission, and (2) a composite of adverse outcomes including all-cause mortality, ventricular tachycardia / ventricular fibrillation (VT/VF) events, appropriate device therapy if an implantable cardioverter defibrillator (ICD) was implanted, stroke and heart failure hospitalization.

Results

The patients had a mean age of 59.0 ± 16.7 years-old at diagnosis and had a male preponderance (71.2%). The most common comorbidities were hypertension, diabetes mellitus and ischemic heart disease. On univariable logistic regression analysis, maximum and minimum left atrial volume index (LAVI) as well as LAEF showed a significant association with heart failure and the predefined composite outcome. On Cox regression analysis adjusting for variables of age, sex, left ventricular ejection fraction (LVEF), left ventricular maximal wall thickness >30mm, significant left ventricular outflow tract (LVOT) gradient of > 30mmHg and more than moderate mitral regurgitation, maximum and minimum LAVI as well as LAEF retained an association with heart failure admission but only minimum LAVI and LAEF were associated with the composite outcome [(OR 0.019, 95% CI 0.02-0.230, p=0.002), (OR 0.226, 95% CI 0.053-0.960, p=0.044), (OR 1.030, 95% CI 1.016-1.045, p<0.001), and (OR 1.016, 95% CI 1.005-1.026, p=0.004) respectively].

Conclusion

LAEF was an independently associated with congestive heart failure as well as a composite of adverse outcomes in Asian patients with HCM.

Prospective associations of circulating thrombospondin-2 level with heart failure hospitalization, left ventricular remodeling and diastolic function in type 2 diabetes

Background

Circulating thrombospondin-2 (TSP2) levels were associated with the development of heart failure (HF) in recent studies. However, these studies included only a minority of patients with type 2 diabetes, which is associated with an increased HF risk. As hyperglycemia induces TSP2 expression and its tissue expression increases in type 2 diabetes, we investigated the prospective association of circulating TSP2 with incident HF hospitalization (HHF), and its associations with longitudinal changes of echocardiographic parameters in type 2 diabetes.

Methods

Baseline serum TSP2 levels were measured in 4949 patients with type 2 diabetes to determine its association with incident HHF using multivariable Cox regression analysis. In the echocardiographic study, baseline serum TSP2 levels were measured in another 146 patients with type 2 diabetes but without cardiovascular diseases who underwent detailed transthoracic echocardiography at baseline and after 1 year.

Results

Over a median follow-up of 7.8 years, 330 of 4949 patients (6.7%) developed incident HHF. Baseline serum TSP2 levels were independently associated with the development of HHF (HR 1.31, 95%CI 1.06–1.62, p = 0.014) after adjustments for baseline conventional cardiovascular risk factors, atrial fibrillation, estimated glomerular filtration rate, albuminuria and high-sensitivity C-reactive protein level, use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, loop-diuretics, aspirin, insulin, metformin and sodium-glucose co-transporter 2 inhibitors. Moreover, baseline serum TSP2 levels were independently associated with increase in average E/e’ and left atrial volume index (p = 0.04 and < 0.01, respectively).

Conclusion

Serum TSP2 levels were independently associated with both incident HHF and deterioration in diastolic function in type 2 diabetes.

Trial registration

Not Applicable

Supplementary information

The online version contains supplementary material available at 10.1186/s12933-022-01646-x.

Protective Effects of Topical Administration of Laminarin in Oxazolone-Induced Atopic Dermatitis-like Skin Lesions

Laminarin is a polysaccharide isolated from brown marine algae and has a wide range of bioactivities, including immunoregulatory and anti-inflammatory properties. However, the effects of laminarin on atopic dermatitis have not been demonstrated. This study investigated the potential effects of topical administration of laminarin using a Balb/c mouse model of oxazolone-induced atopic dermatitis-like skin lesions. Our results showed that topical administration of laminarin to the ear of the mice improved the severity of the dermatitis, including swelling. Histological analysis revealed that topical laminarin significantly decreased the thickening of the epidermis and dermis and the infiltration of mast cells in the skin lesion. Serum immunoglobulin E levels were also significantly decreased by topical laminarin. Additionally, topical laminarin significantly suppressed protein levels of oxazolone-induced proinflammatory cytokines, such as interleukin-1β, tumor necrosis factor-α, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1α in the skin lesion. These results indicate that topical administration of laminarin can alleviate oxazolone-induced atopic dermatitis by inhibiting hyperproduction of IgE, mast cell infiltration, and expressions of proinflammatory cytokines. Based on these findings, we propose that laminarin can be a useful candidate for the treatment of atopic dermatitis.

Sleep apnea and temporal changes in cardiac repolarization in patients undergoing coronary artery bypass grafting

Background

In coronary artery bypass grafting (CABG), despite re-establishing coronary reperfusion, myocardial recovery and restoration of contractility often occur later, and the risk of adverse cardiovascular events persists during the post-CABG period. The occurrence of adverse cardiovascular events is linked to abnorm-al cardiac repolarisation that can be measured by surface electrocardiograms (ECGs). Sleep apnoea is an emerging cardiovascular risk factor. The relationship between sleep apnoea, abnorm-al cardiac repolarisation, and the occurrence of adverse cardiovascular events is not well studied.

Purpose

We investigated the impact of sleep apnoea on the change in repolarisation after CABG, and if the change in repolarisation is associated with the occurrence of major adverse cardiac and cerebrovascular events (MACCE).

Methods

Between November 2013 and December 2018, 1007 patients from 4 hospitals underwent an overnight sleep study prior to a non-emergent CABG. ECGs were acquired prospectively within 48h before the CABG (T1), and within 24h after the CABG (T2). QTc intervals were measured in three consecutive heart beats in one lead - the preferential lead measurements were lead II, followed by lead V5. QTc intervals were measured using the BRAVO algorithm by Analysing Medical Parameters for Solutions (AMPS) LLC. The change of T2 from T1 for QTc (ΔQTc) was derived. The mean follow-up duration was 2.1 years. MACCE was a composite of cardiovascular death, myocardial infarction, stroke, and unplanned revascularisation.

Results

A total of 954 patients (median age: 62 years; male: 86%) survived the initial 24 hours and had quality ECGs for analysis. Lead II and V5 were measured in 72% and 25% of the cohort, respectively. A total of 115 patients developed MACCE (MACCE group). Compared with the non-MACCE group, the MACCE group was older, had (a) a higher prevalence of smoking, hypertension, diabetes mellitus, and chronic kidney disease, (b) higher apnoea-hypopnoea index (AHI) and oxygen desaturation index (ODI), and (c) a smaller ΔQTc (Table). In Cox regression analysis, a smaller ΔQTc was independently associated with occurrence of MACCE (HR: 1.003; 95% CI: 1.000–1.006; p=0.032).

Older age, history of previous stroke, chronic kidney disease, more severe sleep apnoea (higher AHI, ODI, and severe oxygen desaturation) were associated with smaller ΔQTc. After adjusting for the effects of confounding variables, a higher ODI was independently associated with a smaller ΔQTc (correlation coefficient: −0.58; p&lt;0.001).

Conclusions

In patients undergoing a non-emergent CABG, a smaller ΔQTc during the first 24 hours after the CABG is associated with a higher incidence of MACCE. A higher pre-operative ODI based on a sleep study is an independent predictor of a smaller ΔQTc. This suggests that change in QTc within 24 hours after CABG could be due to sleep apnoea, and it is a novel predictor of occurrence of MACCE at medium term follow-up.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Transition Award and Clinician Scientist Award from the National Medical Research Council of Singapore (award numbers: NMRC/TA/012/2012; NMRC/CSA-INV/002/2015)

Metabolic associated fatty liver disease increases risk of adverse events after acute coronary syndrome

 

Metabolic Associated Fatty Liver Disease (MAFLD) was recently introduced as an alternative definition for fatty liver, that has been linked to an increased risk of systemic end-organ damage. However, current studies have not examined the impact of MAFLD on patients presenting with acute coronary syndrome (ACS). Here, we present a retrospective analysis on the short and long-term outcomes of ACS patients with MAFLD.

Methods

A retrospective analysis was conducted in a tertiary care centre. Hepatic steatosis and fibrosis was examined with hepatic steatosis index and fibrosis-4 (FIB-4) index. The primary and secondary outcomes of the analysis were long term all-cause mortality, and in-hospital all-cause mortality, stroke, heart failure and cardiogenic shock respectively. Adjusted analysis was conducted for primary and secondary outcomes with covariates including age, sex, race, type of ACS and previous myocardial infarction.

Results

A total of 5770 patients were included in the analysis, and 21% of ACS patients had concomitant MAFLD. MAFLD resulted in a 23% increase in long-term all-cause mortality compared to non-MAFLD (HR: 1.230, CI: 1.065 to 1.420, p=0.005). MAFLD increased the risk of in-hospital mortality, stroke, heart failure and cardiogenic shock compared to non-MAFLD. A sensitivity analysis conducted based on MAFLD with advance fibrosis, chronic kidney disease and diabetes also demonstrated significantly increased effect size magnitude of all-cause mortality, compared to non-MAFLD.

Conclusion

MAFLD represents an encapsulation of metabolism dysregulation and has been associated with increased risk of systematic disease. The present study shows that MAFLD is associated with significantly increased adverse prognostic outcomes after ACS compared to non-MAFLD. An increase in awareness of MAFLD is required beyond the field of hepatology for improvements in multidisciplinary care and management.

Funding Acknowledgement

Type of funding sources: None.

Reconstructed meta-analysis of percutaneous coronary intervention versus coronary artery bypass grafting for left main disease

Background

Randomized controlled trials (RCTs) comparing percutaneous coronary intervention (PCI) with drug-eluting stents and coronary artery bypass grafting (CABG) for patients with left main coronary artery disease (LMCAD) have reported conflicting results.

Objectives

We performed a systematic review from inception to 23 May 2021 and one-stage reconstructed individual-patient data meta-analysis (IPDMA) that included 10-year mortality outcomes.

Methods

The primary outcome was 10-year all-cause mortality. Secondary outcomes included myocardial infarction (MI), stroke and unplanned revascularization at 5 years. We did IPDMA using published Kaplan-Meier curves to provide individual data points in coordinates and numbers at risk were used to increase the calibration accuracy of the reconstructed data. Shared frailty model or, when proportionality assumptions were not met, a restricted mean survival time model were fitted to compare outcomes between treatment groups.

Results

Of 583 articles retrieved, 5 RCTs were included. A total of 4595 patients from these 5 RCTs were randomly assigned to PCI (N=2297) or CABG (N=2298). The cumulative 10-year all-cause mortality after PCI and CABG was 12.0% versus 10.6% respectively (HR 1.093, 95% CI: 0.925–1.292; p=0.296). PCI conferred similar time-to-MI (RMST ratio 1.006, 95% CI: 0.992–1.021, p=0.391) and stroke (RMST ratio 1.005, 95% CI: 0.998–1.013, p=0.133) at 5 years. Unplanned revascularization was more frequent following PCI compared with CABG (HR 1.807, 95% CI: 1.524–2.144, p&lt;0.001) at 5 years.

Conclusion

This meta-analysis using reconstructed participant-level time-to-event data showed no statistically significant difference in cumulative 10-year all-cause mortality between PCI versus CABG in the treatment of LMCAD.

Funding Acknowledgement

Type of funding sources: None.

Coronary artery bypass grafting versus percutaneous coronary intervention with stenting for multivessel coronary artery disease without left main coronary disease:reconstructed individual patient data

Background and aims

Data are emerging on 10-year mortality comparing coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) with stenting for multivessel disease (MVD) without left main (LM) involvement. We conducted an updated two-stage meta-analysis using reconstructed individual patient data to compare long-term mortality between CABG and PCI for patients with MVD without significant LM coronary disease.

Methods

Medline and Embase databases were searched for articles comparing CABG with PCI for MVD. A two-stage meta-analysis was conducted using reconstructed patient level survival data for all-cause mortality with subgroups by SYNTAX score. The shared-frailty and stratified Cox models were fitted to compare survival endpoints.

Results

We screened 1496 studies and included six randomized controlled trials with 7181 patients. PCI was associated with greater 10-year all-cause mortality risk (HR: 1.282, CI: 1.118–1.469, p&lt;0.001) compared with CABG. In patients with low SYNTAX score, 10-year all-cause mortality after PCI was comparable to CABG (HR: 1.102, 0.822–1.479, p=0.516). However, in patients with moderate to high SYNTAX score, 10-year all-cause mortality was significantly higher after PCI compared with CABG (HR: 1.444, 1.122–1.858, p&lt;0.001; HR: 1.856, 1.380–2.497, p&lt;0.001 respectively).

Conclusion

This updated reconstructed individual patient-data meta-analysis revealed a sustained lower cumulative all-cause mortality of CABG over PCI for multivessel disease without LM involvement.

Funding Acknowledgement

Type of funding sources: None.

A 10-year cohort on prognostic outcomes in patients presenting with acute myocardial infarction complicated by cardiogenic shock and/or cardiac arrest

Background

Cardiogenic shock (CS) and cardiac arrest (CA) complicating acute myocardial infarction (AMI) portend unfavourable outcomes. This study examined the prognosis of patients presenting with AMI complicated by CS and/or CA.

Methods

Consecutive patients presented with AMI to a percutaneous coronary intervention-capable tertiary institution between 2011 and 2021 were studied. Patients were stratified based on the presence or absence of CS (CS+ or CS−) and CA (CA+ or CA−). The primary outcome was 30-day cardiovascular-related mortality. Subgroup analyses based on AMI-type and sex were conducted. Kaplan-Meier curves for cardiovascular-related mortality based on the AMI-type and sex were constructed.

Results

The study included 11,608 AMI patients, 283 of whom had CS+/CA+, 1,068 had CS+/CA−, 54 had CS−/CA+ and 10,203 had CS−/CA−. Cardiovascular-related mortality was significantly higher for CS+/CA+ (57.6%), followed by CS+/CA− (41.6%), CS−/CA+ (20.4%) and CS−/CA− (2.4%). Kaplan-Meier curves demonstrated CS+/CA+ group had the highest mortality (HR=36.26; 95% CI: 29.71–44.25, p&lt;0.001), followed by CS+/CA− (HR=21.59; 95% CI: 18.47–25.24, p&lt;0.001) and CS−/CA+ (HR=9.18; 95% CI: 5.02–16.80, p&lt;0.001), with CS−/CA− as the reference. Those with NSTEMI had consistently higher cardiovascular-related mortality rates than their STEMI counterparts for all groups, apart from the CS+/CA+ group. The sex-specific analysis demonstrated that the survival curves for females with CS+/CA+, CS+/CA− and CS−/CA+ converged, whilst the survival curves for males diverged over time. The multivariable Cox regression revealed the presence of CS and CA are independent predictors of cardiovascular-related mortality, but not NSTEMI, when adjusted for age, gender, diabetes, left ventricular ejection fraction, chronic renal failure, and culprit vessel.

Conclusions

AMI associated with CA and CS portends the least favourable survival, followed by those with CS or CA alone. Excess mortality was observed in the traditionally perceived lower-risk groups, particularly in women. This calls for increased awareness amongst clinicians when managing this subset of high-risk patients.

Funding Acknowledgement

Type of funding sources: None.

Legacy effects of infection in patients with heart failure: a national cohort study of 31,318 patients in Taiwan

Background

Although infection is a common cause of hospitalization in patients (pts) with heart failure (HF), the long-term cardiovascular (CV) prognosis in HF after infection is not well studied.

Methods and results

From 2009 to 2015, 310,485 pts with their first HF admissions and survival to discharge were identified from the National Health Insurance Research Database. Among the pts, 103,505 (33.3%) were readmitted within 1 year after HF discharge for infection, including pneumonia (44.2%), urinary tract infection (UTI) (37.9%), skin and soft tissue infections (9.7%), and others (8.1%). Those without admission for any infection were controls. We compared the primary composite endpoint, including all-cause death, acute myocardial infarction (AMI), stroke, and hospitalization for HF (HHF) between the 2 groups after the infection episode. After propensity score matching, the clinical characteristics (age 71.7±13.9 years, male 52.0%) and treatment were similar between the groups (n=15,659 in each group). In a mean follow-up time of 4.3±2.9 years, 86.2% pts with a history of infection admission and 63.6% pts in the control group met the primary endpoint. Multivariate Cox proportional hazards analysis showed the infection group had a higher risk of the primary composite endpoint (HR 1.760, 95% CI 1.714–1.807), including all-cause death (HR 1.587, 95% CI: 1.540–1.636), HHF (HR 1.993, 95% CI 1.922–2.066), AMI (HR 1.332, 95% CI 1.224–1.450), and stroke (HR 1.769, 95% CI 1.664–1.882). In infection group, HHF was the earliest outcome event with a mean time of 17.5 months and mortality is the second early event with a mean time of 23 months after discharge from the infection episode. Pneumonia carried a higher risk than UTI for the primary composite endpoint (HR 1.140, 95% CI 1.104–1.178).

Conclusions

One-third of HF pts discharged from the hospital experienced acute infection that required readmission. The pts had worse CV prognosis after readmission for infectious disease compared to those without infection

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): This study is supported by National Cheng Kung University Hospital and Tainan Hospital, Ministry of Health and Welfare, Taiwan.

Higher long-term mortality in patients with concomitant acute coronary syndrome and aortic stenosis

Background

Aortic stenosis (AS) and acute coronary syndrome (ACS) share similar cardiovascular risk factors, and their concomitant presentation is increasing in incidence with the aging population. Yet literature regarding the prognosis of patients with concomitant ACS and AS remains scarce.

Methods

This retrospective cohort study examined consecutive patients presenting with ACS (ST-segment elevation myocardial infarction [STEMI] and non-STEMI [NSTEMI]) and concomitant AS between 1 January 2011 and 31 March 2021 in a tertiary hospital. The cohort was divided into mild, moderate and severe AS based on index echocardiogram. The primary outcome was all-cause mortality. Kaplan-Meier curves were constructed to compare all-cause mortality among the three groups of patients, based on ACS type and left ventricular ejection fraction (LVEF). Multivariable Cox regression was performed to identify independent predictors of all-cause mortality.

Results

Of a total of 563 patients, 264 had mild (46.9%), 193 moderate (34.3%) and 106 severe AS (18.8%). The mean follow-up duration was 2.5 (± 2.4) years. Majority of patients (72.5%) presented with NSTEMI. Patients with moderate and severe AS had higher rates of all-cause mortality compared to those with mild AS (49.7% vs. 51.4% vs. 35.6% respectively, p=0.002). Concomitant moderate (HR 1.439, 95% CI 1.012–2.048, p=0.043) and severe AS (HR 1.844, 95% CI 1.159–2.933, p=0.010) were independent predictors of all-cause mortality after adjusting for age, gender, LVEF, ACS type, chronic kidney disease, diabetes, hypertension, coronary artery bypass grafting and aortic valve replacement as a time-dependent variable. The Kaplan-Meier curves demonstrated excess mortality in moderate and severe AS, compared to the mild AS group (p&lt;0.001), with similar survival trends observed in the STEMI and the NSTEMI groups, as well as those with preserved LVEF.

Conclusion

Regardless of the ACS presentation type, long-term excess mortality in those with concomitant moderate or severe AS was observed. The adverse prognosis typically observed in patients with concomitant severe AS, in the setting of ACS, extends to patients with moderate AS.

Funding Acknowledgement

Type of funding sources: None.

Prenatal exposure to nickel and atopic dermatitis at age 3 years: a birth cohort study with cytokine profiles

BACKGROUND

Nickel, the fifth most common element on Earth, is the leading inducer of contact allergies in humans, with potent immunological effects. Nickel-induced contact allergies predominantly affect females. Maternal exposure to nickel has been associated with several developmental abnormalities. However, how a maternal nickel exposure affects the development of atopic diathesis and immune abnormalities in children has never been addressed.

OBJECTIVES

We aimed to determine whether maternal Ni exposure affects the development of atopic dermatitis and immune abnormalities in their children.

METHODS

Using a birth cohort study, we analysed 140 mother-child pairs recruited in 2012-2015 from central Taiwan. Maternal exposure to nickel was estimated using urinary nickel levels measured by inductively coupled plasma mass spectrometry (ICP-MS). The serum levels of 65 analytes and IgE in 3-year-old children were profiled with a multiplex ELISA. The correlation between the maternal urinary nickel concentration and serum analyte levels was assessed using Spearmen's correlation. Multivariant regression analysis was performed to evaluate the association between maternal urinary nickel levels and serum analyte concentrations in their children.

RESULTS

The geometric means of the maternal urinary nickel and the children's serum IgE levels were 2.27 μg/L and 69.71 IU/ml, respectively. The maternal nickel exposure was associated with increased serum levels of IL-1β, IL-2, TNF-α, and leukaemia inhibitory factor (LIF) but with decreased serum levels of matrix metalloproteinase-1 (MMP-1), IL-2R, and eotaxin-1 in the children. In addition, the development of childhood atopic dermatitis at 3 years old was significantly associated with the child's serum levels of IgE and IL-2R, but it was negatively associated with the maternal nickel exposure.

CONCLUSIONS

This is the first study showing the potential immunological effects of maternal nickel exposure in their children at an early developmental stage.

Relationship between Neuronal Damage/Death and Astrogliosis in the Cerebral Motor Cortex of Gerbil Models of Mild and Severe Ischemia and Reperfusion Injury

Neuronal loss (death) occurs selectively in vulnerable brain regions after ischemic insults. Astrogliosis is accompanied by neuronal death. It can change the molecular expression and morphology of astrocytes following ischemic insults. However, little is known about cerebral ischemia and reperfusion injury that can variously lead to damage of astrocytes according to the degree of ischemic injury, which is related to neuronal damage/death. Thus, the purpose of this study was to examine the relationship between damage to cortical neurons and astrocytes using gerbil models of mild and severe transient forebrain ischemia induced by blocking the blood supply to the forebrain for five or 15 min. Significant ischemia tFI-induced neuronal death occurred in the deep layers (layers V and VI) of the motor cortex: neuronal death occurred earlier and more severely in gerbils with severe ischemia than in gerbils with mild ischemia. Distinct astrogliosis was detected in layers V and VI. It gradually increased with time after both ischemiae. The astrogliosis was significantly higher in severe ischemia than in mild ischemia. The ischemia-induced increase of glial fibrillary acidic protein (GFAP; a maker of astrocyte) expression in severe ischemia was significantly higher than that in mild ischemia. However, GFAP-immunoreactive astrocytes were apparently damaged two days after both ischemiae. At five days after ischemiae, astrocyte endfeet around capillary endothelial cells were severely ruptured. They were more severely ruptured by severe ischemia than by mild ischemia. However, the number of astrocytes stained with S100 was significantly higher in severe ischemia than in mild ischemia. These results indicate that the degree of astrogliosis, including the disruption (loss) of astrocyte endfeet following ischemia and reperfusion in the forebrain, might depend on the severity of ischemia and that the degree of ischemia-induced neuronal damage may be associated with the degree of astrogliosis.

Effect of iron deficiency without anaemia on days alive and out of hospital in patients undergoing valvular heart surgery

Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml^-1 or < 300 ng.ml^-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127-141 [120-172]) g.l^-1 , 143 (133-150 [120-179]) g.l^-1 , p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77-82 [9-85]) days vs. 81 (79-83 [0-85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion.

Hyperthermia accelerates neuronal loss differently between the hippocampal CA1 and CA2/3 through different HIF‑1α expression after transient ischemia in gerbils

The hippocampus has a different vulnerability to ischemia according to the subfields CA1 to CA3 (initials of cornu ammonis). It has been reported that body temperature changes during ischemia affect the degree of neuronal death following transient ischemia. Hypoxia-inducible factor 1α (HIF-1α) plays a key role in regulating cellular adaptation to low oxygen conditions. In the present study, we investigated the pattern of neuronal death (loss) in CA1 and CA2/3 following 5 min transient forebrain ischemia (TFI) under hyperthermia (39.5±0.2°C) and the relationship between neuronal death and changes in HIF-1α expression using western blot analysis and immunohistochemistry in gerbils. Normothermia or hyperthermia was induced for 30 min before and during the TFI, and neuronal death and HIF-1α expression were observed at 0, 3, 6 and 12 h, 1, 2 and 5 days after TFI. Under normothermia, TFI-induced neuronal death of CA1 pyramidal neurons occurred on day 5 after TFI, but CA2/3 pyramidal neurons did not die. In contrast, under hyperthermia, the death of CA1 and CA2/3 pyramidal neurons was observed on day 2 after TFI. Under normothermia, HIF-1α expression was significantly elevated in both CA1 and CA2/3 pyramidal neurons at 12 h and 1 day after TFI, and the increased HIF-1α immunoreactivity in CA1 was dramatically reduced from 2 days after TFI, but not in CA2/3 pyramidal neurons. Under hyperthermia, the basal expression of HIF-1α in the sham group was significantly higher in both CA1 and CA2/3 pyramidal neurons at 0 h after TFI than in the normothermia group. HIF-1 expression was continuously higher, peaked at 12 h after TFI, and then significantly decreased from 1 day after TFI. Overall, the present results indicate that resistance to ischemia in CA2/3 pyramidal neurons is closely associated with the persistence of increased expression of HIF-1α after ischemic insults and that hyperthermia-induced exacerbation of death of pyramidal neurons is closely related to decreased HIF-1α expression after ischemic insults.

Non-alcoholic fatty liver disease and type 2 diabetes - An Update

The global prevalence of non‐alcoholic fatty liver disease (NAFLD) is rising, along with the epidemic of diabesity. NAFLD is present in >70% of individuals with type 2 diabetes. Although the mutually detrimental relationship between NAFLD and type 2 diabetes has been well established, a multitude of recent studies have further shown that type 2 diabetes is closely linked to the development of cirrhosis, hepatocellular carcinoma, liver‐related morbidity and mortality. In contrast, NAFLD also negatively impacts type 2 diabetes both in terms of its incidence and related adverse clinical outcomes, including cardiovascular and chronic kidney diseases. In response to these global health threats, clinical care pathways for NAFLD and guidelines for metabolic dysfunction‐associated fatty liver disease have been developed. Several antidiabetic agents have been evaluated for their potential hepatic benefits with promising results. Furthermore, type 2 diabetes patients are increasingly represented in clinical trials of novel therapeutics for NAFLD. However, despite the wealth of knowledge in NAFLD and type 2 diabetes, lack of awareness of the disease and the potential weight of this problem remains a major challenge, especially among clinicians who are outside the field of hepatology and gastroenterology. This review therefore aimed to provide all diabetes care providers with a summary of the latest evidence that supports NAFLD as an emerging diabetic complication of increasing importance, and to present the current recommendations, focusing on the assessment and therapeutic strategies, on the management of NAFLD among type 2 diabetes patients.

Therapeutic effects of stiripentol against ischemia-reperfusion injury in gerbils focusing on cognitive deficit, neuronal death, astrocyte damage and blood brain barrier leakage in the hippocampus

Stiripentol is an anti-epileptic drug for the treating of refractory status epilepticus. It has been reported that stiripentol can attenuate seizure severity and reduce seizure-induced neuronal damage in animal models of epilepsy. The objective of the present study was to investigate effects of post-treatment with stiripentol on cognitive deficit and neuronal damage in the cornu ammonis 1 (CA1) region of the hippocampus proper following transient ischemia in the forebrain of gerbils. To evaluate ischemia-induced cognitive impairments, passive avoidance test and 8-arm radial maze test were performed. It was found that post-treatment with stiripentol at 20 mg/kg, but not 10 or 15 mg/kg, reduced ischemia-induced memory impairment. Transient ischemia-induced neuronal death in the CA1 region was also significantly attenuated only by 20 mg/kg stiripentol treatment after transient ischemia. In addition, 20 mg/kg stiripentol treatment significantly decreased ischemia-induced astrocyte damage and immunoglobulin G leakage. In brief, stiripentol treatment after transient ischemia ameliorated transient ischemia-induced cognitive impairment in gerbils, showing that pyramidal neurons were protected and astrocyte damage and blood brain barrier leakage were significantly attenuated in the hippocampus. Results of this study suggest stiripentol can be developed as a candidate of therapeutic drug for ischemic stroke.

Clinical impact of intravascular ultrasound guidance in patients of ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention with drug eluting stent

Background

There is little data about clinical role of intravascular ultrasound (IVUS)-guided Percutaneous (PCI) in the setting of ST-segment elevation myocardial infarction (STEMI).

Methods

From 2005 to 2018, a total of 8,129 patients who underwent PCI with STEMI were investigated from the Korea Acute Myocardial Infarction Registry-National Institute of Health database. Patients with Non-ST segment elevation myocardial infarction, cardiogenic shock, bare metal stent implantation, thrombolytic treatment, and coronary artery bypass graft surgery were excluded. We categorized patients into two groups based on the treatment strategy: IVUS-guided PCI group (n=1,544), and coronary angiography guidance (CAG)-guided PCI group (n=6,585). The primary endpoint was composite of major adverse cardiovascular (MACE), including, cardiac death, myocardial infarction (MI), repeat target vessel revascularization (TVR) and stent thrombosis (ST).

Results

IVUS-guided PCI was performed in 19% patients (1544/8129). After propensity score matching, there were no statistically difference in the rate of cardiac death (0% in IVUS vs. 0.26% in CAG, p=0.947), MI (2.01% vs. 2.01%, p=0.408), TVR (1.23% vs. 0.91%, p=0.131), ST (0.32% vs. 0.45%, p=0.828) and composite of MACE at 1 year between two groups (2.01% vs. 2.40%, p=0.843). Independent risk factors for MACE were diabetes mellitus and multi-vessel disease, but not IVUS-guided PCI (HR 1.167, 95% CI, 0.896–1.520, p=0.251).

Conclusion

This study suggests that routine usage of IVUS in the setting of STEMI may not be necessary. Large-scaled random study will be needed for further evaluation.

Funding Acknowledgement

Type of funding sources: None.

Neuroprotective and Anti-Inflammatory Effects of Pinus densiflora Bark Extract in Gerbil Hippocampus Following Transient Forebrain Ischemia

Korean red pine (Pinus densiflora) belongs to the Genus Pinus, and its bark contains a great amount of naturally occurring phenolic compounds. Until now, few studies have been conducted to assess the neuroprotective effects of Pinus densiflora bark extract against brain ischemic injury. The aim of this study was to investigate the neuroprotective effects of pre-treatment with the extract in the hippocampus following 5-min transient forebrain ischemia in gerbils. Furthermore, this study examined the anti-inflammatory effect as a neuroprotective mechanism of the extract. Pinus densiflora bark was extracted by pure water (100 °C), and this extract was quantitatively analyzed and contained abundant polyphenols, flavonoids, and proanthocyanidins. The extract (25, 50, and 100 mg/kg) was orally administered once a day for seven days before the ischemia. In the gerbil hippocampus, death of the pyramidal neurons was found in the subfield cornu ammonis 1 (CA1) five days after the ischemia. This death was significantly attenuated by pre-treatment with 100 mg/kg, not 25 or 50 mg/kg, of the extract. The treatment with 100 mg/kg of the extract markedly inhibited the activation of microglia (microgliosis) and significantly decreased the expression of pro-inflammatory cytokines (interleukin 1β and tumor necrosis factor α). In addition, the treatment significantly increased anti-inflammatory cytokines (interleukin 4 and interleukin 13). Taken together, this study clearly indicates that pre-treatment with 100 mg/kg of Pinus densiflora bark extract in gerbils can exert neuroprotection against brain ischemic injury by the attenuation of neuroinflammatory responses.

Changes in Cyclin D1, cdk4, and Their Associated Molecules in Ischemic Pyramidal Neurons in Gerbil Hippocampus after Transient Ischemia and Neuroprotective Effects of Ischemic Preconditioning by Keeping the Molecules in the Ischemic Neurons

Simple Summary

Cyclin D1 and cyclin-dependent kinase 4 (cdk4) is implicated in neuronal death induced by various pathological conditions. Ischemic preconditioning (IPC) confers neuroprotective effect, but underlying mechanisms have been poorly addressed. In this study, IPC protected pyramidal neurons (cells) in gerbil hippocampus after transient ischemia. Additionally, IPC controlled expressions of cyclin D1, cdk4, phosphorylated retinoblastoma (p-Rb), and E2 promoter binding factor 1 (E2F1). In particular, the expression of p16INK4a was not different by IPC. These findings indicate that cyclin D1/cdk4-related signals may play important roles in events in neurons related to damage/death following ischemic insults. Especially, the preservation of p16INK4a by IPC may be crucial in attenuating neuronal death/damage or protecting neurons after brain ischemic insults.

Abstract

Inadequate activation of cell cycle proteins including cyclin D1 and cdk4 is involved in neuronal cell death induced by diverse pathological stresses, including transient global brain ischemia. The neuroprotective effect of ischemic preconditioning is well-established, but the underlying mechanism is still unknown. In this study, we examined changes in cyclin D1, cdk4, and related molecules in cells or neurons located in Cornu Ammonis 1 (CA1) of gerbil hippocampus after transient ischemia for 5 min (ischemia and reperfusion) and investigated the effects of IPC on these molecules after ischemia. Four groups were used in this study as follows: sham group, ischemia group, IPC plus (+) sham group, and IPC+ischemia group. IPC was developed by inducing 2-min ischemia at 24 h before 5-min ischemia (real ischemia). Most pyramidal cells located in CA1 of the ischemia group died five days after ischemia. CA1 pyramidal cells in the IPC+ischemia group were protected. In the ischemia group, the expressions of cyclin D1, cdk4, phosphorylated retinoblastoma (p-Rb), and E2F1 (a transcription factor regulated by p-Rb) were significantly altered in the pyramidal cells with time after ischemia; in the IPC+ischemia group, they were controlled at the level shown in the sham group. In particular, the expression of p16^INK4a (an endogenous cdk inhibitor) in the ischemia group was reversely altered in the pyramidal cells; in the IPC+TI group, the expression of p16^INK4a was not different from that shown in the sham group. Our current results indicate that cyclin D1/cdk4-related signals may have important roles in events in neurons related to damage/death following ischemia and reperfusion. In particular, the preservation of p16^INK4a by IPC may be crucial in attenuating neuronal death/damage or protecting neurons after brain ischemic insults.

Comparison of Neuronal Death, Blood-Brain Barrier Leakage and Inflammatory Cytokine Expression in the Hippocampal CA1 Region Following Mild and Severe Transient Forebrain Ischemia in Gerbils

Transient ischemia in the brain causes blood-brain barrier (BBB) breakdown and dysfunction, which is related to ischemia-induced neuronal damage. Leakage of plasma proteins following transient ischemia is one of the indicators that is used to determine the extent of BBB dysfunction. In this study, neuronal damage/death, leakage of albumin and IgG, microgliosis, and inflammatory cytokine expression were examined in the hippocampal CA1 region, which is vulnerable to transient ischemia, following 5-min (mild) and 15-min (severe) ischemia in gerbils induced by transient common carotid arteries occlusion (tCCAo). tCCAo-induced neuronal damage/death occurred earlier and was more severe after 15-min tCCAo vs. after 5-min tCCAo. Significant albumin and IgG leakage (albumin and IgG immunoreactivity) took 1 or 2 days to begin, and immunoreactivity was markedly increased 5 days after 5-min tCCAo. While, albumin and IgG leakage began to increase 6 h after 15-min tCCAo and remained significantly higher over time than that seen in 5-min tCCAo. IgG immunoreactivity was observed in degenerating neurons and activated microglia after tCCAo, and microglia were activated to a greater extent after 15-min tCCAo than 5-min tCCAo. In addition, following 15-min tCCAo, pro-inflammatory cytokines [tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β)] immunoreactivity was significantly higher than that seen following 5-min tCCAo, whereas immunoreactivity of anti-inflammatory cytokines (IL-4 and IL-13) was lower in 15-min than 5-min tCCAo. These results indicate that duration of tCCAo differentially affects the timing and degree of neuronal damage or loss, albumin and IgG leakage and inflammatory cytokine expression in brain tissue. In addition, more severe BBB leakage is closely related to acceleration of neuronal damage through increased microglial activation and pro-inflammatory cytokine expression in the ischemic hippocampal CA1 region.

Ischemia-Reperfusion under Hyperthermia Increases Heme Oxygenase-1 in Pyramidal Neurons and Astrocytes with Accelerating Neuronal Loss in Gerbil Hippocampus

It has been studied that the damage or death of neurons in the hippocampus is different according to hippocampal subregions, cornu ammonis 1–3 (CA1–3), after transient ischemia in the forebrain, showing that pyramidal neurons located in the subfield CA1 (CA1) are most vulnerable to this ischemia. Hyperthermia is a proven risk factor for brain ischemia and can develop more severe and extensive brain damage related with mortality rate. It is well known that heme oxygenase-1 (HO-1) activity and expression is increased by various stimuli in the brain, including hyperthermia. HO-1 can be either protective or deleterious in the central nervous system, and its roles depend on the expression levels of enzymes. In this study, we investigated the effects of hyperthermia during ischemia on HO-1 expression and neuronal damage/death in the hippocampus to examine the relationship between HO-1 and neuronal damage/death following 5-min transient ischemia in the forebrain using gerbils. Gerbils were assigned to four groups: (1) sham-operated gerbils with normothermia (Normo + sham group); (2) ischemia-operated gerbils with normothermia (Normo + ischemia group); (3) sham-operated gerbils with hyperthermia (39.5 ± 0.2 °C) during ischemia (Hyper + sham group); and (4) ischemia-operated gerbils with hyperthermia during ischemia (Hyper + ischemia group). HO-1 expression levels in CA1–3 of the Hyper + ischemia group were significantly higher than those in the Normo + ischemia group. HO-1 immunoreactivity in the Hyper + ischemia group was significantly increased in pyramidal neurons and astrocytes with time after ischemia, and the immunoreactivity was significantly higher than that in the Normo + ischemia group. In the Normo + Ischemia group, neuronal death was shown in pyramidal neurons located only in CA1 at 5 days after ischemia. However, in the Hyper + ischemia group, pyramidal neuronal death occurred in CA1–3 at 2 days after ischemia. Taken together, our findings showed that brain ischemic insult during hyperthermic condition brings up earlier and severer neuronal damage/death in the hippocampus, showing that HO-1 expression in neurons and astrocytes is different according to brain subregions and temperature condition. Based on these findings, we suggest that hyperthermia in patients with ischemic stroke must be taken into the consideration in the therapy.

Potential role of fibroblast growth factor 21 in the deterioration of bone quality in impaired glucose tolerance

PURPOSE

Findings on trabecular bone score (TBS), an index of bone quality, have been reported in prediabetes defined by impaired fasting glucose or HbA1c. Here, we assessed the bone mineral density (BMD) and TBS in prediabetes individuals with impaired glucose tolerance (IGT), and investigated the association of these bone parameters with serum levels of fibroblast growth factor 21 (FGF21), a hormone implicated in bone metabolism and with higher levels in IGT.

METHODS

Chinese postmenopausal women aged 55-80 years, without diabetes, were recruited from the Hong Kong Cardiovascular Risk Factor Prevalence Study in 2016-2018. Normal glucose tolerance (NGT) was defined by fasting glucose < 5.6 mmol/L and 2-h plasma glucose (2hG) < 7.8 mmol/L, and IGT by 2hG 7.8-11 mmol/L. Serum levels of FGF21 and other bone metabolism regulators were measured. Insulin sensitivity was assessed by the Matsuda index. Independent determinants of TBS were evaluated using multivariable stepwise linear regression.

RESULTS

173 individuals with NGT and 73 with IGT were included. TBS was lower in those with IGT compared to those with NGT, while BMD was comparable. Individuals with IGT had significantly higher serum FGF21 levels, which in turn showed an independent inverse relationship with TBS, attenuated after inclusion of the Matsuda index. Serum FGF21 levels, however, did not correlate with BMD.

CONCLUSION

Among Chinese postmenopausal women, bone quality was worse in IGT, despite comparable bone density. FGF21 levels showed a significant independent inverse relationship with TBS, partly attributed to insulin resistance. Whether FGF21 contributes to the impaired bone quality in IGT remains speculative.

CD200 Change Is Involved in Neuronal Death in Gerbil Hippocampal CA1 Field Following Transient Forebrain Ischemia and Postischemic Treatment with Risperidone Displays Neuroprotection without CD200 Change

It has been reported that CD200 (Cluster of Differentiation 200), expressed in neurons, regulates microglial activation in the central nervous system, and a decrease in CD200 expression causes an increase in microglial activation and neuronal loss. The aim of this study was to investigate time-dependent changes in CD200 expression in the hippocampus proper (CA1, 2, and 3 fields) after transient forebrain ischemia for 5 min in gerbils. In this study, 5-min ischemia evoked neuronal death (loss) of pyramidal neurons in the CA1 field, but not in the CA2/3 fields, at 5 days postischemia. In the sham group, CD200 expression was found in pyramidal neurons of the CA1 field, and the immunoreactivity in the group with ischemia was decreased at 6 h postischemia, dramatically increased at 12 h postischemia, decreased (to level found at 6 h postischemia) at 1 and 2 days postischemia, and significantly increased again at 5 days postischemia. At 5 days postischemia, CD200 immunoreactivity was strongly expressed in microglia and GABAergic neurons. However, in the CA3 field, the change in CD200 immunoreactivity in pyramidal neurons was markedly weaker than that in the CA1 field, showing there was no expression of CD 200 in microglia and GABAergic neurons. In addition, treatment of 10 mg/kg risperidone (an atypical antipsychotic drug) after the ischemia hardly changed CD200 immunoreactivity in the CA1 field, showing that CA1 pyramidal neurons were protected from the ischemic injury. These results indicate that the transient ischemia-induced change in CD200 expression may be associated with specific and selective neuronal death in the hippocampal CA1 field following transient forebrain ischemia.

Neuronal Death in the CNS Autonomic Control Center Comes Very Early after Cardiac Arrest and Is Not Significantly Attenuated by Prompt Hypothermic Treatment in Rats

Autonomic dysfunction in the central nervous system (CNS) can cause death after recovery from a cardiac arrest (CA). However, few studies on histopathological changes in animal models of CA have been reported. In this study, we investigated the prevalence of neuronal death and damage in various brain regions and the spinal cord at early times after asphyxial CA and we studied the relationship between the mortality rate and neuronal damage following hypothermic treatment after CA. Rats were subjected to 7-8 min of asphyxial CA, followed by resuscitation and prompt hypothermic treatment. Eight regions related to autonomic control (the cingulate cortex, hippocampus, thalamus, hypothalamus, myelencephalon, and spinal cord) were examined using cresyl violet (a marker for Nissl substance) and Fluoro-Jade B (a marker for neuronal death). The survival rate was 44.5% 1 day post-CA, 18.2% 2 days post-CA and 0% 5 days post-CA. Neuronal death started 12 h post-CA in the gigantocellular reticular nucleus and caudoventrolateral reticular nucleus in the myelencephalon and lamina VII in the cervical, thoracic, lumbar, and sacral spinal cord, of which neurons are related to autonomic lower motor neurons. In these regions, Iba-1 immunoreactivity indicating microglial activation (microgliosis) was gradually increased with time after CA. Prompt hypothermic treatment increased the survival rate at 5 days after CA with an attenuation of neuronal damages and death in the damaged regions. However, the survival rate was 0% at 12 days after CA. Taken together, our study suggests that the early damage and death of neurons related to autonomic lower motor neurons was significantly related to the high mortality rate after CA and that prompt hypothermic therapy could increase the survival rate temporarily after CA, but could not ultimately save the animal.

HbA1c variability, in addition to mean HbA1c, predicts incident hip fractures in Chinese people with type 2 diabetes

Type 2 diabetes is associated with an increased risk of hip fractures. We hypothesize that long-term glycemic variability predicts incident hip fractures. We demonstrated that HbA1c variability predicted incident hip fractures independent of mean HbA1c, suggesting the potential benefits of minimizing glycemic variability in addition to optimizing mean glycemia for bone health.

INTRODUCTION

Type 2 diabetes is associated with an increased risk of hip fractures, and a linear relationship between HbA1c levels and hip fracture incidence has been observed. We hypothesize that HbA1c variability also predicts incident hip fractures in type 2 diabetes.

METHODS

Chinese individuals with type 2 diabetes aged ≥ 60 years were identified from electronic health records in Hong Kong between 2008 and 2012 and observed for incident hip fractures. Hip fracture was defined by the International Classification of Diseases (Ninth Revision) code 820. HbA1c variability was determined using standard deviation, adjusted standard deviation, and coefficient of variation of HbA1c measurements in the 5 years preceding the entry date. Multivariable Cox regression analysis was used to evaluate associations between HbA1c variability and incident hip fractures.

RESULTS

A total of 83,282 participants were included. Their mean age was 71.3 ± 7.5 years, duration of diabetes 11.7 ± 7.7 years, baseline HbA1c 56.6 ± 13.5 mmol/mol (7.33 ± 1.23%), and median follow-up 6.8 years. All indices of HbA1c variability were significant independent predictors of incident hip fractures, with an adjusted hazard ratio of up to 1.29 (all p < 0.001), and remained to be independent predictors across groups of different intensity of glycemic control. Mean HbA1c ≥ 64 mmol/mol (8.0%) was associated with a 25% increase in incident hip fractures compared with mean HbA1c < 53 mmol/mol (7.0%).

CONCLUSION

HbA1c variability is an independent positive predictor of hip fracture in type 2 diabetes, across the spectrum of varying degree of glycemic control, while a high HbA1c is also not advisable from the perspective of bone health.

GW190521: A Binary Black Hole Merger with a Total Mass of 150 M_{⊙}

On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85_{-14}^{+21}  M_{⊙} and 66_{-18}^{+17}  M_{⊙} (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova processes, with only a 0.32% probability of being below 65  M_{⊙}. We calculate the mass of the remnant to be 142_{-16}^{+28}  M_{⊙}, which can be considered an intermediate mass black hole (IMBH). The luminosity distance of the source is 5.3_{-2.6}^{+2.4}  Gpc, corresponding to a redshift of 0.82_{-0.34}^{+0.28}. The inferred rate of mergers similar to GW190521 is 0.13_{-0.11}^{+0.30}  Gpc^{-3} yr^{-1}.

Age‑dependent alterations in the immunoreactivity of macrophage inflammatory protein‑3α and its receptor CCR6 in the gerbil hippocampus

Neuroinflammation is a primary characteristic of the aging brain. During normal aging, macrophage inflammatory protein-3α (MIP-3α) and its receptor C-C chemokine receptor type 6 (CCR6) serve pivotal roles in the neuroinflammatory process in the brain. The aim of the present study was to investigate age-dependent alterations in the immunoreactivity of MIP-3α and CCR6 in the gerbil hippocampus at postnatal month (PM) 1, 6, 12 and 24 via immunohistochemistry. In the PM 1 group, both MIP-3α and CCR6 immunoreactivity were observed primarily in the stratum pyramidale in the hippocampus proper and in the granule cell layer in the dentate gyrus. In the PM 6 and PM 12 groups, MIP-3α in the stratum pyramidale and granule cell layer was decreased compared with the PM 1 group, and CCR6 immunoreactivity in both layers was faint. In the PM 24 group, MIP-3α expression in the stratum pyramidale and granule cell layer was higher than that in the PM 1 group, and CCR6 immunoreactivity in both layers was increased compared with the PM 12 group; however, it was decreased compared with the PM 1 group. In conclusion, MIP-3α and CCR6 immunoreactivity were altered in the hippocampus during normal aging. The results of the current study suggested that age-dependent alterations of MIP-3α and CCR6 may be associated with age-related neuroinflammation in the hippocampus.

Comparison of neuronal death and expression of TNF‑α and MCT4 in the gerbil hippocampal CA1 region induced by ischemia/reperfusion under hyperthermia to those under normothermia

Monocarboxylate transporter 4 (MCT4) is a high-capacity lactate transporter in cells and the alteration in MCT4 expression harms cellular survival. The present study investigated whether hypothermia affects tumor necrosis factor-α (TNF-α) and MCT4 immunoreactivity in the subfield cornu ammonis 1 (CA1) following cerebral ischemia/reperfusion (IR) in gerbils. Hypothermia was induced for 30 min before and during ischemia. It was found that IR-induced death of pyramidal neurons was markedly augmented and occurred faster under hyperthermia than under normothermia. TNF-α immunoreactivity in the pyramidal cells started to increase at 3 h after IR and peaked at 1 day after IR under normothermia. However, in hyperthermic control and sham operated gerbils, TNF-α immunoreactivity was significantly increased compared with the normothermic gerbils, and IR under hyperthermia caused a more rapid and significant increase in TNF-α immunoreactivity in pyramidal neurons than under normothermia. In addition, in the normothermic gerbils, MCT4 immunoreactivity began to decrease in pyramidal neurons from 3 h after IR and markedly increased at 1 and 2 days after IR. On the other hand, MCT4 immunoreactivity in pyramidal neurons of the hyperthermic gerbils was significantly increased from 3 h after IR, maintained until 1 day after IR and markedly decreased at 2 days after IR. These results indicate that acceleration of IR-induced neuronal death under hyperthermia might be closely associated with early alteration of TNF-α and MCT4 protein expression in the gerbil hippocampus after IR.

Change of Nurr1 expression in mouse hippocampal CA3 region following excitotoxic neuronal damage

Objective(s):

Nuclear receptor-related protein 1 (Nurr1), one of immediate-early genes, is a member of orphan nuclear receptor family. The aim of this study was to investigate the time-dependent change of Nurr1 protein expression in the mouse hippocampal CA3 region following kainic acid (KA)-induced excitotoxic neuronal damage.

Materials and Methods:

Male ICR mice were used as experimental animals, and 30 mg/kg KA was administered intraperitoneally. To confirm the KA-induced neuronal damage in the hippocampal CA3 region, Fluoro-Jade B histofluorescence staining was performed. In addition, the time-dependent change of Nurr1 protein expression was also examined using immunohistochemistry and western blot analysis.

Results:

Marked neuronal damage was observed in the hippocampal CA3 region at 24 hr after KA injection. In addition, both Nurr1 immunoreactivity and protein level were significantly increased at 6 hr and 12 hr after KA injection, and then decreased at 24 hr after KA injection.

Conclusion:

This result indicates that KA-induced alteration of Nurr1 protein expression may be associated with the neuronal degeneration in the hippocampal CA3 region after KA injection.

Factors affecting the dormancy and germination of bleeding heart [Lamprocapnos spectabilis (L.) Fukuhara] seeds

Information on the optimal conditions to promote the germination of Lamprocapnos spectabilis (L.) Fukuhara seeds is limited; consequently, this study was conducted to establish the requirements to break seed dormancy and promote germination. The selected seeds had morphophysiological dormancy and had not begun embryo development. To study the dormancy breaking and embryo development processes, seeds were subjected to constant or changing temperature treatments during moist stratification. High temperature and humidity resulted in vigorous embryo growth, with the longest embryos occurring after 1 month of incubation at 20 °C. At 4 °C, the seeds required incubation period of at least 3 months to germinate. Embryo growth and germination were higher with changing high and low temperatures than under a constant temperature, and changing temperatures also considerably changed the endogenous hormone levels, embryo development and germination. Bioactive gibberellin (GA) content was higher in seeds incubated at 20 °C for 1 month, then at 4 °C for 2 months. The content of endogenous abscisic acid in seeds subjected to the same treatment decreased by 97.6% compared with that of the untreated seeds. Embryo growth and seed germination require changing high and low temperatures; however, exogenous GA₃ could substitute for high temperatures, as it also causes accelerated germination. In this study, the seeds of L. spectabilis were identified as an intermediate simple type, a sub-level of morphophysiologically dormant seeds.

p66shc siRNA-Encapsulated PLGA Nanoparticles Ameliorate Neuropathic Pain Following Spinal Nerve Ligation

p66shc, a member of the shc adaptor protein family, has been shown to participate in regulation of mitochondrial homeostasis, apoptosis, and autophagosome formation. The present study was performed to investigate whether p66shc siRNA-encapsulated poly(d,l-lactic-co-glycolic acid) nanoparticles (p66shc siRNA-PLGA NPs) can attenuate spinal nerve ligation (SNL)-induced neuropathic pain in rats. The SNL-induced pain behavior was decreased in the p66shc siRNA-PLGA NP-treated group compared with the scrambled siRNA-PLGA NP-treated group. In the L5 spinal cord of the p66shc siRNA-PLGA NP-treated group, expression levels of phosphorylated p66shc, cleaved caspase-3, p62, and PINK1, as well as microglial activation, were also decreased. In addition, p66shc knockdown using p66shc siRNA reduced the expression levels of cleaved caspase-3, p62, and PINK1, as well as proinflammatory mediators in the H₂O₂-treated HT22 neuronal cells. These results suggest that downregulation of p66shc expression in the spinal cord using p66shc siRNA-PLGA NPs could reduce the SNL-induced neuropathic pain by attenuating the SNL-induced aberrant autophagic, mitophagic, and neuroinflammatory processes in rats.

Protein expression changes of HCN1 and HCN2 in hippocampal subregions of gerbils during the normal aging process

Objective(s):

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels play essential roles in various hippocampal functions, including regulation of long-term potentiation, synaptic plasticity, and hippocampal-dependent cognitive process. The objective of this study was to investigate age-related changes in HCN1 and HCN2 protein expressions in gerbil hippocampus at various ages.

Materials and Methods:

In this study, the protein expressions of HCN1 and HCN2 were compared in the hippocampus at the ages of 1, 3, 12, and 24 months using Western blot analysis and immunohistochemistry.

Results:

Immunoreactivity of both HCN1 and HCN2 was shown primarily in cells of the pyramidal cell layer in the hippocampus proper and in cells of the granule cell layer in the dentate gyrus. HCN1 and HCN2 protein expression levels and immunoreactivity were significantly increased at three months (3 M) of age compared with those at 1 M of age. After that, both HCN1 and HCN2 expression levels in the hippocampus were gradually decreased with age.

Conclusion:

Our results show that the normal aging process affects the expression levels of HCN1 and HCN2 in hippocampal cells in gerbils. There are marked reductions in HCN1 and HCN2 expressions in the aged hippocampus compared to the young hippocampus. Such reductions might be related to aging in the hippocampus.

Randomly Hopping Majorana Fermions in the Diluted Kitaev System α-Ru_{0.8}Ir_{0.2}Cl_{3}

dc and ac magnetic susceptibility, magnetization, specific heat, and Raman scattering measurements are combined to probe low-lying spin excitations in α-Ru_{1-x}Ir_{x}Cl_{3} (x≈0.2), which realizes a disordered spin liquid. At intermediate energies (ℏω>3  meV), Raman spectroscopy evidences linearly ω-dependent Majorana-like excitations, obeying Fermi statistics. This points to robustness of a Kitaev paramagnetic state under spin vacancies. At low energies below 3 meV, we observe power-law dependences and quantum-critical-like scalings of the thermodynamic quantities, implying the presence of a weakly divergent low-energy density of states. This scaling phenomenology is interpreted in terms of the random hoppings of Majorana fermions. Our results demonstrate an emergent hierarchy of spin excitations in a diluted Kitaev honeycomb system subject to spin vacancies and bond randomness.

Novel functions for 2-phenylbenzimidazole-5-sulphonic acid: Inhibition of ovarian cancer cell responses and tumour angiogenesis

In this study, we investigated the effects and molecular mechanisms of 2‐phenylbenzimidazole‐5‐sulphonic acid (PBSA), an ultraviolet B protecting agent used in sunscreen lotions and moisturizers, on ovarian cancer cell responses and tumour angiogenesis. PBSA treatment markedly blocked mitogen‐induced invasion through down‐regulation of matrix metalloproteinase (MMP) expression and activity in ovarian cancer SKOV‐3 cells. In addition, PBSA inhibited mitogen‐induced cell proliferation by suppression of cyclin‐dependent kinases (Cdks), but not cyclins, leading to pRb hypophosphorylation and G₁ phase cell cycle arrest. These anti‐cancer activities of PBSA in ovarian cancer cell invasion and proliferation were mediated by the inhibition of mitogen‐activated protein kinase kinase 3/6‐p38 mitogen‐activated protein kinase (MKK3/6‐p38^MAPK) activity and subsequent down‐regulation of MMP‐2, MMP‐9, Cdk4, Cdk2 and integrin β1, as evidenced by treatment with p38^MAPK inhibitor SB203580. Furthermore, PBSA suppressed the expression and secretion of vascular endothelial growth factor in SKOV‐3 cells, leading to inhibition of capillary‐like tubular structures in vitro and angiogenic sprouting ex vivo. Taken together, our results demonstrate the pharmacological effects and molecular targets of PBSA on modulating ovarian cancer cell responses and tumour angiogenesis, and suggest further evaluation and development of PBSA as a promising chemotherapeutic agent for the treatment of ovarian cancer.

Altered Nurr1 protein expression in the hippocampal CA1 region following transient global cerebral ischemia

Nuclear receptor related 1 protein (Nurr1), a member of the nuclear receptor 4 family of orphan nuclear receptors, has been reported to display anti‑inflammatory properties. The present study investigated the alteration of Nurr1 immunoreactivity in the gerbil hippocampus proper following 5 min of transient global cerebral ischemia. In sham operated gerbils, Nurr1 immunoreactivity was observed in pyramidal neurons in all cornu ammonis 1‑3 (CA1‑3) subfields of the hippocampus proper. In ischemia‑operated gerbils, Nurr1 immunoreactivity was altered in the CA1 subfield. Nurr1 immunoreactivity in CA1 pyramidal neurons gradually decreased until 2 days post‑ischemia, and, at 4 days post‑ischemia, Nurr1 immunoreactivity was concentrated in CA1 pyramidal neurons. Additionally, Nurr1 immunoreactivity was newly expressed in microglia in the CA1 subfield at 4 days post‑ischemia. Conversely, in the CA2/3 subfield, time‑dependent alteration of Nurr1 immunoreactivity was not identified at any time following ischemia. These results indicated that the alteration of Nurr1 expression in the CA1 subfield in the hippocampus may be associated with the death of CA1 pyramidal neurons.

Search for Subsolar Mass Ultracompact Binaries in Advanced LIGO's Second Observing Run

We present a search for subsolar mass ultracompact objects in data obtained during Advanced LIGO's second observing run. In contrast to a previous search of Advanced LIGO data from the first observing run, this search includes the effects of component spin on the gravitational waveform. We identify no viable gravitational-wave candidates consistent with subsolar mass ultracompact binaries with at least one component between 0.2  M_{⊙}-1.0  M_{⊙}. We use the null result to constrain the binary merger rate of (0.2  M_{⊙}, 0.2  M_{⊙}) binaries to be less than 3.7×10^{5}  Gpc^{-3} yr^{-1} and the binary merger rate of (1.0  M_{⊙}, 1.0  M_{⊙}) binaries to be less than 5.2×10^{3}  Gpc^{-3} yr^{-1}. Subsolar mass ultracompact objects are not expected to form via known stellar evolution channels, though it has been suggested that primordial density fluctuations or particle dark matter with cooling mechanisms and/or nuclear interactions could form black holes with subsolar masses. Assuming a particular primordial black hole (PBH) formation model, we constrain a population of merging 0.2  M_{⊙} black holes to account for less than 16% of the dark matter density and a population of merging 1.0  M_{⊙} black holes to account for less than 2% of the dark matter density. We discuss how constraints on the merger rate and dark matter fraction may be extended to arbitrary black hole population models that predict subsolar mass binaries.

Stronger antioxidant enzyme immunoreactivity of Populus tomentiglandulosa extract than ascorbic acid in rat liver and kidney

Objective(s):

Populus species have various pharmacological properties, including antioxidant activity. In this study, the effects of Populus tomentiglandulosa extract (PTE) on histopathology and antioxidant enzymes in the rat liver and kidney were examined.

Materials and Methods:

Sprague-Dawley rats were assigned to three groups; (1) normal diet fed group, (2) ascorbic acid-containing diet-fed group as a positive control, (3) PTE-containing diet-fed group. The histopathology in the rat liver and kidney was examined by hematoxylin and eosin staining. The effect of PTE was examined in the rat liver and kidney by immunohistochemistry for antioxidant enzymes, such as superoxide dismutases (SOD1 and SOD2), catalase (CAT), and glutathione peroxidase (GPx).

Results:

No marked histopathological alterations were observed in the liver and kidney of the PTE-containing diet-fed group. In the liver, the mean numbers of SOD1, SOD2, CAT, and GPx immunoreactive cells were significantly increased in the PTE-containing diet-fed rats, compared with those in the normal- and ascorbic acid-containing diet-fed rats. In the kidney, all SOD1, SOD2, CAT, and GPx immunoreactive structures were significantly increased in the PTE-containing diet-fed group, compared with those in the normal- and ascorbic acid-containing diet-fed groups.

Conclusion:

Results showed that PTE treatment significantly increased antioxidant enzymes in the rat liver and kidney, and we suggest that PTE might have hepato- and nephro-protective potentials against oxidative stress.

Improved HCN channels in pyramidal neurons and their new expression levels in pericytes and astrocytes in the gerbil hippocampal CA1 subfield following transient ischemia

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels have been known to participate in the regulation of neuronal excitability, synaptic transmission and long-term potentiation in the hippocampus. The present study investigated transient ischemia-induced changes of HCN1 and HCN2 expressions in the Cornu Ammonis 1 (CA1) subfield of the hippocampus in gerbils subjected to 5 min transient global cerebral ischemia (tgCI). Neuronal death was exhibited in pyramidal neurons of the striatum pyramidale in the CA1 subfield 4 days after tgCI. HCN1 and HCN2 immunoreactivities were demonstrated in intact CA1 pyramidal neurons, and were transiently and markedly increased in the CA pyramidal neurons at 6 h after ischemia. Thereafter, they gradually decreased in a time-dependent manner. A total of 4 days after ischemia, HCN1 and HCN2 immunoreactivities were barely detected in the CA1 pyramidal neurons; however, HCN1 and HCN2 were began to be expressed in pericytes and astrocytes at 4 days after ischemia. The results indicated that HCN1 and HCN2 expression levels were apparently changed in the gerbil hippocampal CA1 subfield following tgCI and suggested that ischemia-induced alterations in HCN1 and HCN2 expression levels may be closely associated with the death of CA1 pyramidal neurons following 5 min of tgCI.