Day-night pattern of acute ST-segment elevation myocardial infarction onset in patients with obstructive sleep apnea

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is associated with acute nocturnal hemodynamic and neurohormonal abnormalities that may increase the risk of coronary events, especially during the nighttime. This study sought to investigate the day-night pattern of acute ST-segment elevation myocardial infarction (STEMI) onset in patients with OSA and its impact on cardiovascular adverse events.

METHODS

We prospectively enrolled 397 patients with STEMI, for which the time of onset of chest pain was clearly identified. All participants were categorized into non-OSA (n = 280) and OSA (n = 117) groups. The association between STEMI onset time and major adverse cardiovascular and cerebrovascular events was estimated by Cox proportional hazards regression.

RESULTS

STEMI onset occurred from midnight to 5:59 am in 33% of patients with OSA, as compared with 15% in non-OSA patients (P < .01). For individuals with OSA, the relative risk of STEMI from midnight to 5:59 am was 2.717 [95% confidence interval (CI) 1.616 - 4.568] compared with non-OSA patients. After a median of 2.89 ± 0.78 years follow-up, symptom onset time was found to be significantly associated with risk of major adverse cardiovascular and cerebrovascular events in patients with OSA, while there was no significant association observed in non-OSA patients. Compared with STEMI presenting during noon to 5:59 pm, the hazard ratios for major adverse cardiovascular and cerebrovascular events in patients with OSA were 4.683 (95% CI 2.024 - 21.409, P = .027) for midnight to 5:59 am and 6.964 (95% CI 1.379 - 35.169, P = .019) for 6 pm to midnight, whereas the hazard ratios for non-OSA patients were 1.053 (95% CI 0.394 - 2.813, P = .917) for midnight to 5:59 am and 0.745 (95% CI 0.278 - 1.995, P = .558) for 6 pm to midnight.

CONCLUSIONS

Patients with OSA exhibited a peak incidence of STEMI between midnight and 5:59 am, which showed an independent association with cardiovascular adverse events.

CITATION

Wang Y, Buayiximu K, Zhu T, et al. Day-night pattern of acute ST-segment elevation myocardial infarction onset in patients with obstructive sleep apnea. J Clin Sleep Med. 2024;20(5):765-775.

Safety and efficacy of glibenclamide combined with rtPA in acute cerebral ischemia with occlusion/stenosis of anterior circulation (SE-GRACE): a randomized, double-blind, placebo-controlled trial

Background

Glibenclamide alleviates brain edema and improves neurological outcomes in experimental models of stroke. We aimed to assess whether glibenclamide improves functional outcomes in patients with acute ischemic stroke treated with recombinant tissue plasminogen activator (rtPA).

Methods

In this randomized, double-blind, placebo-controlled trial, patients with acute ischemic stroke were recruited to eight academic hospitals in China. Patients were eligible if they were aged 18-74 years, presented with a symptomatic anterior circulation occlusion with a deficit on the NIHSS of 4-25, and had been treated with rtPA within 4.5 h of symptom onset. We used web-based randomization (1:1) to allocate eligible participants to the glibenclamide or placebo group, stratified according to endovascular treatment and baseline stroke severity. Glibenclamide or placebo was taken orally or via tube feeding at a loading dose of 1.25 mg within 10 h after symptom onset, followed by 0.625 mg every 8 h for 5 days. The primary outcome was the proportion of patients with good outcomes (modified Rankin Scale of 0-2) at 90 days, assessed in all randomly assigned patients who had been correctly diagnosed and had begun study medication. The study is registered with ClinicalTrials.gov, NCT03284463, and is closed to new participants.

Findings

Between January 1, 2018, and May 28, 2022, 305 patients were randomly assigned, of whom 272 (142 received glibenclamide and 130 received placebo) were included in the primary efficacy analysis. 103 (73%) patients in the glibenclamide group and 94 (72%) in the placebo group had a good outcome (adjusted risk difference 0.002, 95% CI -0.098 to 0.103; p = 0.96). 12 (8%) patients allocated to glibenclamide and seven (5%) patients allocated to placebo died from any cause at 90 days (p = 0.35). The number and type of adverse events were similar between the two groups. There were no drug-related adverse events and no drug-related deaths.

Interpretation

The addition of glibenclamide to thrombolytic therapy did not increase the proportion of patients who achieved good outcomes after stroke compared with placebo, but it did not lead to any safety concerns.

Funding

Southern Medical University and Nanfang Hospital.

A novel bivalent anti-c-MET/PD-1 bispecific antibody exhibits potent cytotoxicity against c-MET/PD-L1-positive colorectal cancer

Previously, we generated a novel bispecific antibody (BsAb) simultaneously targeting both c-MET and PD-1 (PDCD1), which can bridge T cells and c-MET positive tumor cells. However, the specific mechanisms and antitumor activities of the BsAb against c-MET/PD-L1 (CD274) positive colorectal cancer (CRC) is not completely understood. In this study, in addition to the tumor intrinsic mechanism investigation with molecular biology assay in vitro, a humanized mouse model was used to evaluate antitumor activity of the BsAb in vivo. The BsAb could inhibit c-MET/PD-L1+ CRC cell migration and show strong antitumor activity against HCT116 tumors in mice, potentially by inducing the degradation of c-MET protein in a dose and time-dependent manner. The BsAb could suppress the phosphorylation of c-MET downstream proteins GRB2-associated-binding protein 1 (Gab1) and focal adhesion kinase (FAK). Considering the tumor extrinsic mechanism, the BsAb may promote phagocytosis of macrophage. Furthermore, the level of plasma exosomal-c-MET/PD-L1 is able to distinguish CRC patients from healthy controls. In summary, the BsAb exhibited potent anti-tumor activities by two distinguished mechanisms: inhibition of c-MET signal transduction and promotion of macrophage-mediated phagocytosis. Our BsAb may provide a novel therapeutic agent for patients with c-MET/PD-L1+ CRC, and the status of exosomal-c-MET/PD-L1 can serve as a biomarker to predict responsiveness to treatment of our BsAb.

Predictive value of early left ventricular end-diastolic volume changes for late left ventricular remodeling after ST-elevation myocardial infarction

BACKGROUD

Left ventricular remodeling (LVR) is a major predictor of adverse outcomes in patients with acute ST-elevation myocardial infarction (STEMI). This study aimed to prospectively evaluate LVR in patients with STEMI who were successfully treated with primary percutaneous coronary intervention (PCI) and examine the relationship between early left ventricular dilation and late LVR.

METHODS

Overall 301 consecutive patients with STEMI who underwent primary PCI were included. Serial echocardiography was performed on the first day after PCI, on the day of discharge, at 1 month, and 6 months after discharge.

RESULTS

Left ventricular remodeling occurred in 57 (18.9%) patients during follow-up. Left ventricular end-diastolic volume (LVEDV) reduced from day 1 postoperative to discharge in the LVR group compared with that in the non-LVR (n-LVR) group. The rates of change in LVEDV (ΔLVEDV%) were -5.24 ± 16.02% and 5.05 ± 16.92%, respectively (p < 0.001). LVEDV increased in patients with LVR compared with n-LVR at 1-month and 6-month follow-ups (ΔLVEDV% 13.05 ± 14.89% vs. -1.9 ± 12.03%; 26.46 ± 14.05% vs. -3.42 ± 10.77%, p < 0.001). Receiver operating characteristic analysis showed that early changes in LVEDV, including ΔLVEDV% at discharge and 1-month postoperative, predicted late LVR with an area under the curve value of 0.80 (95% confidence interval 0.74-0.87, p < 0.0001).

CONCLUSIONS

Decreased LVEDV at discharge and increased LVEDV at 1-month follow-up were both associated with late LVR at 6-month. Comprehensive and early monitoring of LVEDV changes may help to predict LVR.

Semicrystalline IrOx with Abundant Boundaries for Overall Water Splitting

Inorganic compounds with different crystalline and amorphous states may show distinct properties in catalytic applications. In this work, we control the crystallization level by fine thermal treatment and synthesize a semicrystalline IrO_x material with the formation of abundant boundaries. Theoretical calculation reveals that the interfacial iridium with a high degree of unsaturation is highly active for the hydrogen evolution reaction compared to individual counterparts based on the optimal binding energy with hydrogen (H*). At the heat treatment temperature of 500 °C, the obtained IrO_x-500 catalyst has dramatically promoted hydrogen evolution kinetics, endowing the iridium catalyst with a bifunctional activity for acidic overall water splitting with a total voltage of only 1.554 V at a current density of 10 mA cm^-2. In light of the remarkable boundary-enhanced catalysis effects, the semicrystalline material should be further developed for other applications.

Association of Serum BAFF Levels with Cardiovascular Events in ST-Segment Elevation Myocardial Infarction

OBJECTIVES

The B cell activating factor (BAFF) is a B cell survival factor involved in atherosclerosis and ischemia-reperfusion (IR) injury. This study sought to investigate whether BAFF is a potential predictor of poor outcomes in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

We prospectively enrolled 299 patients with STEMI, and serum levels of BAFF were measured. All subjects were followed for three years. The primary endpoint was major adverse cardiovascular events (MACEs), including cardiovascular death, nonfatal reinfarction, hospitalization for heart failure (HF), and stroke. Multivariable Cox proportional hazards models were constructed to analyze the predictive value of BAFF for MACEs.

RESULTS

In multivariate analysis, BAFF was independently associated with risk of MACEs (adjusted HR 1.525, 95% CI 1.085-2.145; p = 0.015) and cardiovascular death (adjusted hazard ratio [HR] 3.632, 95% confidence interval [CI] 1.132-11.650, p = 0.030) after adjustment for traditional risk factors. Kaplan-Meier survival curves demonstrated that patients with BAFF levels above the cut-off value (1.46 ng/mL) were more likely to have MACEs (log-rank p < 0.0001) and cardiovascular death (log-rank p < 0.0001). In subgroup analysis, the impact of high BAFF on MACEs development was stronger in patients without dyslipidemia. Furthermore, the C-statistic and Integrated Discrimination Improvement (IDI) values for MACEs were improved with BAFF as an independent risk factor or when combined with cardiac troponin I.

CONCLUSIONS

This study suggests that higher BAFF levels in the acute phase are an independent predictor of the incidence of MACEs in patients with STEMI.

Influence of LDL-Cholesterol Lowering on Coronary Plaque Progression of Non-Target Lesions in Patients Undergoing Percutaneous Coronary Intervention: Findings from a Retrospective Study

The progression of NTLs after PCI accounts for a significant portion of future adverse cardiac events. The reduction in LDL-C reduces cardiovascular events. This has, however, not yet been shown in a real-world setting. We aimed to investigate the association between LDL-C changes with progression in NTLs. A total of 847 patients with successful PCI were enrolled. Patients with follow-up LDL-C ≥ 1.4 mmol/L or percent reduction <50% compared to baseline were Non-optimal group (n = 793); patients with follow-up LDL-C < 1.4 mmol/L and percent reduction ≥50% compared to baseline were Optimal group (n = 54). Compared to Non-optimal group, Optimal group presented a lower rate of NTL plaque progression (11.11% vs. 23.96%; p = 0.007) and a lower follow-up TC (2.77 ± 0.59 vs. 3.66 ± 0.97; p < 0.001) and LDL-C (1.09 ± 0.26 vs. 2.03 ± 0.71; p < 0.001). The univariate logistic regression analysis revealed that follow-up LDL-C < 1.4 mmol/L and a percent reduction ≥50% from baseline was a protective factor for NTL plaque progression (OR: 0.397; 95%CI: 0.167-0.941; p = 0.036). The multivariate logistic regression model revealed that follow-up LDL-C < 1.4 mmol/L and percent reduction ≥50% was indeed an independent factor associated with a lower rate of plaque progression of NTLs (OR: 0.398; 95% CI: 0.167-0.945; p = 0.037). Therefore, achieving guideline-recommended LDL-C level was associated with a significantly reduced risk of NTL plaque progression.

[68Ga]Ga-DOTA-FAPI-04 PET/MR in patients with acute myocardial infarction: potential role of predicting left ventricular remodeling

PURPOSE

To assess predictive value of ⁶⁸Ga-labeled fibroblast activation protein inhibitor-04 ([⁶⁸Ga]Ga-DOTA-FAPI-04) PET/MR for late left ventricular (LV) remodeling in patients with ST-segment elevated myocardial infarction (STEMI).

METHODS

Twenty-six patients with STEMI were included in the study. [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/MR was performed at baseline and at average 12 months after STEMI. LV remodeling was defined as >10% increase in LV end-systolic volume (LVESV) from baseline to 12 months.

RESULTS

The LV remodeling group demonstrated higher [⁶⁸Ga]Ga-DOTA-FAPI-04 uptake volume (UV) at baseline than the non-LV remodeling group (p < 0.001). [⁶⁸Ga]Ga-DOTA-FAPI-04 UV at baseline was a significant predictor (OR = 1.048, p = 0.011) for LV remodeling at 12 months after STEMI. Compared to clinical information, MR imaging and cardiac function parameters at baseline, [⁶⁸Ga]Ga-DOTA-FAPI-04 UV demonstrated better predictive ability (AUC = 0.938, p < 0.001) for late LV remodeling, with sensitivity of 100.0% and specificity of 81.3%.

CONCLUSIONS

[⁶⁸Ga]Ga-DOTA-FAPI-04 PET/MR is an effective tool to non-invasively quantify myocardial fibroblasts activation, and baseline [⁶⁸Ga]Ga-DOTA-FAPI-04 UV may have potential predictive value for late LV remodeling.

Strategies for Electrochemically Sustainable H2 Production in Acid

Acidified water electrolysis with fast kinetics is widely regarded as a promising option for producing H₂ . The main challenge of this technique is the difficulty in realizing sustainable H₂ production (SHP) because of the poor stability of most electrode catalysts, especially on the anode side, under strongly acidic and highly polarized electrochemical environments, which leads to surface corrosion and performance degradation. Research efforts focused on tuning the atomic/nano structures of catalysts have been made to address this stability issue, with only limited effectiveness because of inevitable catalyst degradation. A systems approach considering reaction types and system configurations/operations may provide innovative viewpoints and strategies for SHP, although these aspects have been overlooked thus far. This review provides an overview of acidified water electrolysis for systematic investigations of these aspects to achieve SHP. First, the fundamental principles of SHP are discussed. Then, recent advances on design of stable electrode materials are examined, and several new strategies for SHP are proposed, including fabrication of symmetrical heterogeneous electrolysis system and fluid homogeneous electrolysis system, as well as decoupling/hybrid-governed sustainability. Finally, remaining challenges and corresponding opportunities are outlined to stimulate endeavors toward the development of advanced acidified water electrolysis techniques for SHP.

Monocyte/High-Density Lipoprotein Ratio Predicts the Prognosis of Large Artery Atherosclerosis Ischemic Stroke

Objective: Monocyte to high-density lipoprotein ratio is considered as a new inflammatory marker and has been used to predict the severity of coronary heart disease and the incidence of adverse cardiovascular events (ACEs). However, there is a lack of data relative to large artery atherosclerosis (LAA) ischemic stroke. We investigated whether the monocyte to high-density lipoprotein (HDL) ratio (MHR) is related to the 3-month functional prognosis of LAA ischemic stroke.

Materials and Methods: A retrospective analysis was conducted on 316 LAA ischemic stroke patients. The 3-month functional outcome was divided into good and poor according to the modified Rankin Scale (mRS) score. Multivariate logistic regression analysis was performed to evaluate the correlation between MHR and prognosis of ischemic stroke.

Results: The MHR level of poor functional outcome group was higher than that of the good functional outcome group [0.44 (0.3, 0.55) vs. 0.38 (0.27, 0.5), P = 0.025]. Logistic stepwise multiple regression revealed that MHR [odds ratio (OR) 9.464, 95%CI 2.257–39.678, P = 0.002] was an independent risk factor for the 3-month poor outcome of LAA ischemic stroke. Compared to the lower MHR tertile, the upper MHR tertile had a 3.03-fold increase (95% CI 1.475–6.225, P = 0.003) in the odds of poor functional outcome after adjustment for potential confounders. Moreover, a multivariable-adjusted restricted cubic spline (RCS) showed a positive close to a linear pattern of this association.

Conclusion: Elevated MHR was independently associated with an increased risk of poor 3-month functional outcome of patients with LAA ischemic stroke.

Electrochemical CO2 Reduction on Cu: Synthesis-Controlled Structure Preference and Selectivity

The electrochemical CO2 reduction reaction (ECO2 RR) on Cu catalysts affords high-value-added products and is therefore of great practical significance. The outcome and kinetics of ECO2 RR remain insufficient, requiring essentially the optimized structure design for the employed Cu catalyst, and also the fine synthesis controls. Herein, synthesis-controlled structure preferences and the modulation of intermediate's interactions are considered to provide synthesis-related insights on the design of Cu catalysts for selective ECO2 RR. First, the origin of ECO2 RR intermediate-dominated selectivity is described. Advanced structural engineering approaches, involving alloy/compound formation, doping/defect introduction, and the use of specific crystal facets/amorphization, heterostructures, single-atom catalysts, surface modification, and nano-/microstructures, are then reviewed. In particular, these structural engineering approaches are discussed in association with diversified synthesis controls, and the modulation of intermediate generation, adsorption, reaction, and additional effects. The results pertaining to synthetic methodology-controlled structural preferences and the correspondingly motivated selectivity are further summarized. Finally, the current opportunities and challenges of Cu catalyst fabrication for highly selective ECO2 RR are discussed.

In situ surface reduction for accessing atomically dispersed platinum on carbon sheets for acidic hydrogen evolution

Exploring the simple yet well-controlled synthesis of atomically dispersed Pt catalysts is a crucial endeavour for harvesting clean hydrogen via the kinetics-favoured acidic electrochemical water splitting technique. Here we employed the use of defective carbon sheets by KOH etching as a substrate for the in situ surface reduction of Pt(IV) ions to prepare atomically dispersed Pt. Physical and electrochemical characterizations reveal a strong interaction between the carbon substrate and Pt species, providing the basis for the in situ surface reduction. The atomically dispersed Pt electrocatalyst exhibited high HER performance in a sulfuric acid electrolyte, with an overpotential as low as 55 mV at a current density of 100 mA cm^-a, and better catalytic durability compared to the commercial Pt/C. The mechanism study revealed that the full utilization of atomically dispersed Pt and the optimized catalyst surface may enhance the recombination of adsorbed *H via the Volmer-Tafel mechanism to produce H₂ at a high efficiency. In the light of high activity, durability, and low cost, the atomically dispersed Pt material is promising for acidic HER application.

Well-dispersed tin nanoparticles encapsulated in amorphous carbon tubes as high-performance anode for lithium ion batteries

Tin/carbon (Sn/C) nanocomposite is considered as a promising anode material for high-performance Li-ion batteries (LIBs). However, since the carbon matrix is always derived from high-temperature carbonization of polymers and Sn has a low melting point (232 °C), the Sn nanoparticles in the Sn/C tend to be heavily aggregated during the carbonization process. It is thus challenging to synthesize well-dispersed Sn nanoparticles in a carbon matrix. Here, we report a facile templating method to encapsulate uniform well-dispersed Sn nanoparticles in amorphous carbon tube (Sn@aCT). The electrode fabricated with the hierarchical Sn@aCT exhibits excellent cycle performance. A stable specific capacity of 870 mAh g^-1 after 350 cycles and a Li-ion diffusion coefficient as high as [Formula: see text] are obtained. Meanwhile, the intermediate structure of SnO₂@aCT and a carbon-coated Sn yolk-shell nanostructure (Sn@C-YS) are investigated for comparison. The results further manifest the advantage of the architecture of the Sn@aCT. Our strategy provides a feasible way to optimize Sn/C nanocomposite as a high-performance anode material for LIBs.

Serum MG53/TRIM72 Is Associated With the Presence and Severity of Coronary Artery Disease and Acute Myocardial Infarction

Background: Mitsugumin 53 or Tripartite motif 72 (MG53/TRIM72), a myokine/cardiokine belonging to the tripartite motif family, can protect the heart from ischemic injury and regulate lipid metabolism in rodents. However, its biological function in humans remains unclear. This study sought to investigate the relationship between circulating MG53 levels and coronary artery disease (CAD). Methods: The concentration of MG53 was measured by enzyme-linked immunosorbent assay (ELISA) in serum samples from 639 patients who underwent angiography, including 205 controls, 222 patients with stable CAD, and 212 patients with acute myocardial infarction (AMI). Logistic and linear regression analyses were used to analyze the relationship between MG53 and CAD. Results: MG53 levels were increased in patients with stable CAD and were highest in patients with AMI. Additionally, patients with comorbidities, such as chronic kidney disease (CKD) and diabetes also had a higher concentration of MG53. We found that MG53 is a significant diagnostic marker of CAD and AMI, as analyzed by logistic regression models. Multivariate linear regression models revealed that serum MG53 was significantly corelated positively with SYNTAX scores. Global Registry of Acute Coronary Events (GRACE) scores also correlated with serum MG53 levels, indicating that MG53 levels were associated with the severity of CAD and AMI after adjusting for multiple risk factors and clinical biomarkers. Conclusion: MG53 is a valuable diagnostic marker whose serum levels correlate with the presence and severity of stable CAD and AMI, and may represent a novel biomarker for diagnosing CAD and indicating the severity of CAD.

Prognostic Value of Circulating MG53 Levels in Acute Myocardial Infarction

Background: Mitsugumin 53 (MG53), a muscle-specific protein belonging to the TRIM family, has been demonstrated to protect the heart against oxidative injury. Although previous studies indicated that ischemic hearts released MG53 into circulation in mice, its effects in humans remains unknown. We aimed to evaluate the prognostic value of MG53 in patients with ST-segment elevation myocardial infarction (STEMI).

Methods: Serum levels of MG53 were measured in 300 patients with STEMI, all patients were followed for 3 years. The primary endpoint was major adverse cardiovascular events (MACE), defined as a composite of cardiovascular (CV) death, heart failure causing-rehospitalization, recurrent myocardial infarction (MI), and stroke.

Results: Patients with a higher concentration of serum MG53 tended to be older, with a history of diabetes. MG53 levels were also highly associated with indicators reflecting heart function, such as left ventricular ejection fraction (LVEF), N terminal pro B type natriuretic peptide (NT-pro-BNP), and cardiac troponin I (cTnI) at baseline. Kaplan-Meier survival curves demonstrated that patients with MG53 levels above the cutoff value (132.17 pg/ml) were more likely to have MACEs. Moreover, it was found to be a significant predictor of CV death (HR: 6.12; 95% CI: 2.10–17.86; p = 0.001). Furthermore, the C-statistic and Integrated Discrimination Improvement (IDI) values for MACEs were improved with MG53 as an independent risk factor or when combined with cTnI.

Conclusions: MG53 is a valuable prognostic marker of MACE in patients with AMI, independent of established conventional risk factors, highlighting the significance of MG53 in risk stratification post-MI.

Left atrial size and risk of recurrent ischemic stroke in cardiogenic cerebral embolism

BACKGROUND

Left atrial enlargement (LAE) was reported to be associated with ischemic stroke and its recurrence. Limited data are available on the relationship of LAE and cardiogenic cerebral embolism (CCE). Our aim is to access the association of left atrial size and the recurrence of ischemic stroke in CCE.

METHODS

We prospectively included 303 CCE patients who underwent transthoracic echocardiography (TTE). Left atrial size was estimated with left atrial diameter (LAD), diameter/height (LAD/H), and left atrial diameter/body surface area (LAD/BSA). The endpoint was one-year recurrent ischemic stroke. Cox proportional hazard models were performed to access the association between left atrial size and recurrent ischemic stroke.

RESULTS

During follow-up, 27 patients suffered recurrent ischemic stroke. In multivariate COX regression models adjusted for confounders including age, gender, hypertension, diabetes, and history of stroke or transient ischemic attack (TIA), platelet count, fasting blood glucose (FBG), antithrombotic drugs at discharge, stroke volume, and cardiac output, LAD, LAD/H, and LAD/BSA all were independent risk factors of recurrent ischemic stroke [LAD: HR 1.065, 95% CI (1.006-1.128), p = .029; LAD/H: HR 1.157, 95% CI (1.066-1.255), p < .001; LAD/BSA: HR 1.128, 95% CI (1.059-1.202), p < .001]. Receiver-operator characteristic curves showed that LAD/BSA had better predicting effect. The area under the curve (AUC) was 0.543 [95%CI (0.444-0.642), p = .461) for LAD, 0.626 [95%CI (0.530-0.723), p = .03] for LAD/H, and 0.655 [95%CI (0.558-0.752), p = .008] for LAD/BSA.

CONCLUSION

LAE is an independent risk factor for one-year recurrence of ischemic stroke in patients with CCE.

Expression level of lncRNA PVT1 in serum of patients with coronary atherosclerosis disease and its clinical significance

OBJECTIVE

The purpose of this study was to detect the expression level of PVT1 in the serum of coronary artery disease (CAD) patients, and to explore the clinical significance of PVT1 in CAD.

PATIENTS AND METHODS

A total of 200 CAD patients and 200 healthy controls in the same period were included. The serum level of PVT1 in every subject was detected. Then, the correlation between PVT1 level and Gensini score in CAD patients was analyzed by Spearman correlation test. Finally, multivariable Logistic regression test was conducted to assess risk factors influencing coronary atherosclerosis disease.

RESULTS

It was found that PVT1 was highly expressed in the serum of CAD patients and its level was correlated with Gensini score (r=0.761, p=0.023). Besides, multivariable Logistic regression test obtained that PVT1 was the risk factor influencing coronary atherosclerosis disease (crude OR = 2.074, 95% CI: 1.642-3.529; adjusted OR = 1.762, 95% CI: 1.382-2.096).

CONCLUSIONS

Serum level of PVT1 helps to distinguish mild and severe CAD. Meanwhile, PVT1 is an independent risk factor influencing the development of coronary atherosclerosis disease.

Efficacy of Zotarolimus-Eluting Stents in Treating Diabetic Coronary Lesions: An Optical Coherence Tomography Study

BACKGROUND

Diabetes mellitus (DM) plays an important role in restenosis and late in-stent thrombosis (ST). The current study using optical coherence tomography (OCT) aims to compare target lesion neointima in patients with or without diabetes after zotarolimus-eluting stent (ZES) treatment.

METHODS

OCT images of 90,212 struts and quantitative coronary angiography (QCA) in 62 patients (32 with DM and 30 without DM) with 69 de novo coronary lesions (34 DM and 35 non-DM) both after ZES implantation and 12 ± 1 month angiographic follow-up were recorded. Patient characteristics, lesion characteristics, clinical outcomes, and OCT findings including neointimal thickness, coverage, malapposition, and intimal morphology were analyzed.

RESULTS

Baseline patient characteristics and lesion characteristics data were similar between the two groups. Higher neointimal thickness (0.14 ± 0.09 mm vs. 0.09 ± 0.04 mm, p = 0.021), more neovascularization (3.03 ± 6.24 vs. 0.52 ± 1.87, p = 0.017) and higher incidence of layered signal pattern (12.19 ± 19.91% vs. 4.28 ± 9.02%, p = 0.049) were observed in diabetic lesions comparing with non-diabetic lesions. No differences were found in malapposition, uncovered percentage, and thrombus between the two groups (all p > 0.05). Occurrence of clinical adverse events was also similar during the follow-up period (p > 0.05).

CONCLUSION

Although more neointimal proliferation and more neovascularization were found in diabetic coronary lesions when compared with non-diabetic lesions, treatment with ZES showed similar stent malapposition rate at 1-year follow-up. The data indicated that ZES treatment could possibly be effective in treating diabetic coronary lesions.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01747356.

Broadband, millimeter-wave antireflection coatings for large-format, cryogenic aluminum oxide optics

We present two prescriptions for broadband ($ {\sim} 77 - 252\;{\rm GHz} $), millimeter-wave antireflection coatings for cryogenic, sintered polycrystalline aluminum oxide optics: one for large-format (700 mm diameter) planar and plano-convex elements, the other for densely packed arrays of quasi-optical elements-in our case, 5 mm diameter half-spheres (called "lenslets"). The coatings comprise three layers of commercially available, polytetrafluoroethylene-based, dielectric sheet material. The lenslet coating is molded to fit the 150 mm diameter arrays directly, while the large-diameter lenses are coated using a tiled approach. We review the fabrication processes for both prescriptions, then discuss laboratory measurements of their transmittance and reflectance. In addition, we present the inferred refractive indices and loss tangents for the coating materials and the aluminum oxide substrate. We find that at 150 GHz and 300 K the large-format coating sample achieves $ (97 \pm 2)\% $ transmittance, and the lenslet coating sample achieves $ (94 \pm 3)\% $ transmittance.

Incidence and mortality of nasopharyngeal carcinoma: interim analysis of a cluster randomized controlled screening trial (PRO-NPC-001) in southern China

BACKGROUND

Previous mass screening studies have shown that IgA antibodies against Epstein-Barr Virus (EBV) can facilitate early detection of nasopharyngeal carcinoma (NPC), but the impact of EBV-antibody screening for NPC-specific mortality remains unknown.

PATIENTS AND METHODS

A prospective, cluster randomized, controlled trial for NPC screening (PRO-NPC-001) was conducted in 3 selected towns of Zhongshan City and 13 selected towns of Sihui City in southern China beginning in 2008. Serum samples of the screening group were tested for two previously selected anti-EBV antibodies. Subjects with serological medium risk were subsequently retested annually for 3 years, and those with serological high risk were referred to otorhinolaryngologists for diagnostic check-up. An interim analysis was carried out to evaluate the primary end points of the NPC-specific mortality and the early diagnostic rate, and the secondary end point of the NPC incidence, through linkage with the database of Zhongshan City.

RESULTS

Among 70 296 total subjects, 29 413 screened participants (41.8% of the total subjects) in the screening group and 50 636 in the control group, 153 (43.3 per 100 000 person-year), 62 (55.3 per 100 000 person-year) and 99 (33.1 per 100 000 person-year) NPC cases were identified. The early diagnostic rates of NPC were significantly higher in the participants (79.0%, P < 0.0001) and the screening group (45.9%, P < 0.0001) compared with the control group (20.6%). Although no differences were found between NPC-specific mortality of the screening group and the control group [relative risk (RR)= 0.82, 95% confidence interval (CI) 0.37-1.79], lower NPC-specific mortality was noticed among participants from the screening group versus the control group (RR = 0.22, 95% CI 0.09-0.49).

CONCLUSION

IgA antibodies against EBV can identify high-risk population and was effective in screening for early asymptomatic NPC. Although the mortality reduction was not significant in the primary end point, we noted encouraging evidence of a mortality reduction in screening participants in this interim analysis.

CLINICAL TRIAL NUMBER

NCT00941538.

High Risk Characteristics for Recurrent Cardiovascular Events among Patients with Obstructive Sleep Apnoea in the SAVE Study

BACKGROUND

Obstructive sleep apnoea (OSA) is a common comorbidity in patients with cardiovascular (CV) disease. We aimed to identify specific OSA clinical phenotypes relating to risks of serious CV events and response to continuous positive airway pressure (CPAP) treatment.

METHODS

Post-hoc analyses of the Sleep Apnea Cardiovascular Endpoints (SAVE) study in participants with moderate-to-severe OSA and coronary artery disease (CAD) and/or cerebrovascular disease (CeVD) randomised to CPAP plus usual care or usual care alone. Latent class analysis (LCA) was used to identify OSA clinical phenotypes among 2649 (out of 2687 total) patients with complete data on 19 patient-centered variables, supported by Bayesian information criteria and clinical interpretability. Cox regression models were used to evaluate risks of composite cardiac and stroke outcome events in phenotype groups. Preferential response to CPAP treatment was evaluated using interaction terms as well as the Chi-square test.

FINDINGS

LCA identified four OSA clinical phenotypes: CAD alone and with diabetes mellitus (CAD + DM), and CeVD alone and with DM (CeVD + DM), in 39%, 15%, 37% and 9% of participants, respectively. The rates of composite CV events were the highest in CAD + DM phenotype (HR 2.08, 95% CI 1.57-2.76) and for stroke were highest in CeVD + DM phenotype (HR 6.84, 95% CI 3.77-12.42). Adherence to CPAP treatment (nil or < 4 h vs ≥ 4 h in the first two years of the study) was shown to influence the risk of composite CV outcome in the phenotypes (P-interaction = 0.04); CPAP adherent patients of the CeVD + DM phenotype had the lowest risk of CV outcome (P = 0.02).

INTERPRETATION

High risk clinical phenotypes were identified in relation to CV events and response to CPAP treatment, which may allow improved targeting of therapies in OSA patients.

FUNDING

The National Health and Medical Research Council (NHMRC) of Australia, Fisher & Paykel Healthcare, and ResMed.

Large-size and high performance visible-light photodetectors based on two-dimensional hybrid materials SnS/RGO

We report a facile solvothermal method to synthesize two-dimensional hybrid materials consisting of layered SnS nanosheets and reduced graphene oxide (SnS/RGO). Large-size photodetectors with a channel length/width = 2 mm/7 mm are fabricated on Si/SiO₂ substrates, showing an excellent photoresponsivity of 0.18 A W⁻¹ under visible-light illumination with a detectivity of 4.18 × 10¹⁰ Jones, as well as fast rise and decay times (τ_rise = τ_decay = 0.4 s). SnS/RGO hybrids are therefore promising candidates for potential applications in optoelectronics and low cost, high performance, and reliable photodetectors.

We report a facile solvothermal method to synthesize hybrid materials SnS/RGO which are promising candidates for potential applications in photodetectors.

A QTL with Major Effect on Reducing Stripe Rust Severity Detected From a Chinese Wheat Landrace

Stripe rust, a devastating disease of wheat worldwide, can be controlled by use of diverse wheat resistance resources. To find new quantitative trait loci (QTL) for resistance to stripe rust, Qing Shumai (a Chinese winter wheat landrace possessing slow rusting resistance) was crossed with the susceptible line Mingxian 169. The parents and 276 recombinant inbred lines (RILs) from the cross were evaluated in five environments involving two locations (Gansu and Shandong provinces, China) and four autumn-sown wheat seasons (2008 to 2012). Disease severities on Qing Shumai were lower than 25%, contrasting with approximately 90% on Mingxian 169. The RILs varied in rust intensity in a continuous and monomodal distribution. A bulked segregant analysis approach using 2,344 simple sequence repeat (SSR) markers mapped a major QTL to the long arm of chromosome 6D (hereby designated as QYr.cau-6DL). An SSR marker (gpw5179, https://wheat.pw.usda.gov/GG2/index.shtml ) was identified as being tightly linked with QYr.cau-6DL. Combination between QYr.cau-6DL and the stripe rust-resistance gene Yr18 was examined using 160 F_2:3 families of Qing Shumai × RL6058 (a near-isogenic line for Yr18 in the genetic background of the spring wheat Thatcher). The combination elevated the resistance consistently across both winter and spring wheat backgrounds, acting synergistically without undesired epistasis.

Low serum levels of uric acid and albumin in patients with Guillain-Barre syndrome

Free radical toxicity due to poorly maintained cellular redox levels is crucial events that have been associated with the pathogenesis of Guillain-Barre syndrome (GBS) patients. Uric acid (UA) and albumin correlate with oxidative stress in some degree. We aimed to evaluate the relationship between GBS and serum levels of UA and albumin in the present study.The serum levels of UA and albumin were determined in 203 individuals including 88 patients with GBS and 153 healthy controls (HC).We found that serum levels of UA and albumin in patients with GBS were significantly lower than those in HC group. Besides, similar phenomenon was observed when the male and female subgroups were estimated, respectively. Additionally, we found that there is no statistic difference among subgroups of GBS regarding UA and albumin. The univariate analysis revealed that both the high UA and high albumin were protective factors for patients with GBS (odds ratio [OR] 0.140; 95% confidence interval [CI]: 0.074-0.264; P < .001 and OR 0.016; 95% CI: 0.006-0.038; P < .001, respectively). It was further confirmed by the multivariable logistic regression analysis after adjusting for other potential confounding factors (OR 0.168; 95% CI: 0.055-0.514; P = .002 and OR 0.027; 95% CI: 0.011-0.071; P < .001, respectively).In conclusion, we found that patients with GBS had significantly low serum UA and albumin levels. Moreover, we demonstrated that both the high UA and high albumin were protective factors for patients with GBS.

Thyroid hormone level is associated with the frequency and severity of Guillain-Barré syndrome

OBJECTIVE

Guillain-Barré syndrome (GBS) is a neurodegenerative and inflammatory demyelination disorder, and oxidative stress is concerned with the pathogenesis of the disease. Also, we found that thyroid hormone level is correlated to the oxidative and antioxidant status in previous studies. Our study was aimed to find the possible relationship between the frequency and severity of GBS and thyroid hormone levels.

MATERIALS AND METHODS

We measured serum levels of thyroid-stimulating hormone (TSH), free thyroxine (FT₄) and free triiodothyronine (FT₃) in 238 individuals, including 90 GBS, 44 multiple sclerosis and 104 healthy controls.

RESULTS

Our findings demonstrate that the patients with GBS had lower TSH and higher FT_4, FT₄/FT₃ than healthy controls in the normal range. Furthermore, it was also shown in our study that TSH levels in patients with GBS were correlated with disease severity measured by the Hughes Functional Grading Scale.

CONCLUSION

Lower TSH, higher FT₄ and FT₄/FT₃ stand for the oxidative status and are associated with the incidence and severity of GBS.

Antioxidant status of serum bilirubin and uric acid in patients with polymyositis and dermatomyositis

OBJECTIVE

Oxidative stress and variations in antioxidant status are implicated in the pathogenesis of inflammatory and autoimmune diseases. Polymyositis and dermatomyositis (PM/DM) are autoimmune diseases with inflammatory cells infiltrating into skeletal muscles, and the antioxidant status is still controversial. The aim of our study was to investigate the correlation between PM/DM and the antioxidant status of serum bilirubin (Tbil, Dbil and Ibil) and uric acid (UA).

MATERIALS AND METHODS

We measured serum concentrations of bilirubin (Tbil, Dbil and Ibil) and uric acid in 384 individuals, including 110 PM/DM patients and 274 healthy controls.

RESULTS

We found that PM/DM patients had significantly lower serum concentrations of bilirubin (Tbil and Ibil) and uric acid than healthy controls, whether male or female. Also, after separately adjusting the covariances of age and gender, Tbil, Dbil, Ibil and UA were all relevant factors for PM/DM. Moreover, there were no significant differences in serum antioxidant molecule levels between PM and DM subgroups.

CONCLUSION

Our study demonstrated the low serum levels of bilirubin and uric acid in patients with PM/DM. This suggested low antioxidant status in PM/DM patients with excessive oxidative stress.

Fiber-optic current sensor with self-compensation of source wavelength changes

We demonstrate a method for self-compensation of scale factor changes of an interferometric fiber-optic current sensor caused by source wavelength shifts, e.g., due to changes in source temperature or drive current. An adequately tailored fiber-optic retarder in the optical circuit introduces wavelength-dependent mixing of the orthogonal polarization modes of the sensor. The resulting change in scale factor balances the variation of the Faraday effect with wavelength. The wavelength dependence of the sensor is suppressed by more than an order of magnitude to <0.2% over wavelength spans of at least 10 nm around 1305 nm. The retarder is designed as an athermal device for operation between -40°C and 80°C.

Facile preparation of free-standing rGO paper-based Ni–Mn LDH/graphene superlattice composites as a pseudocapacitive electrode

A novel film electrode was assembled via a simple filtration process, with an rGO paper as the substrate and Ni–Mn LDH/graphene superlattice composites as the functional layer.

Diagnostic outcomes of magnetocardiography in patients with coronary artery disease

OBJECTIVE

To evaluate the diagnostic outcomes of magnetocardiography (MCG) on the patients with coronary artery disease and compared the outcomes between MCG, ECG and Echocardiography.

METHODS

MCG measurements were performed on 101 patients with coronary artery disease and 116 healthy volunteers with a seven-channel magnetocardiographic system (MCG7, SQUID AG, Germany) installed in an unshielded room. CAD was diagnosed when stenosis ≥ 70% in ≥ 1 vessel. Three quantitative indicators were analyzed, R-max/T-max ratio, R value and á average angle.

RESULTS

R-max/T-max ratio of CAD group (6.30 ± 4.07) was much higher than that of healthy group (3.73 ± 1.41) (P < 0.001), R value of CAD group (69.16 ± 27.87)% was significantly higher than that of healthy group (34.96 ± 19.09)% (P < 0.001), á average angle of CAD group (221.46° ± 64.53°) was higher than that of healthy group (24.32° ± 20.70°) (P < 0.01). In 75 of 101 CAD patients (74.26%), MCG had abnormal mapping patterns. The resting ECG examination showed ischemic changes, such as abnormal Q waves and ST-T change in 49 patients (48.51%). Echocardiography revealed abnormal left ventricular wall motion and asynergy in 46 patients (45.54%). Thus, the diagnostic outcomes of MCG for the patients with CAD were much significant than those of ECG and echocardiography (P < 0.001).

CONCLUSIONS

Our result showed that resting MCG under condition of an advanced data analysis has higher diagnostic outcomes and is superior to ECG or echocardiography for patients with CAD. MCG can detect ST-segment displacement caused by ischemic myocardium, thus helpful in diagnosing coronary artery disease early.

A case of pulmonary infiltrates in a patient with colon carcinoma

A 31-year-old white male with a known history of colon carcinoma was referred to the Interventional Pulmonary service for right lower lobe infiltrates and mucous plugging on computed tomography with concern for pneumonia. Bronchoscopy was performed revealing a broad based mass completely obstructing the bronchus intermedius. It was possible to pass a probe into the right lower lobe, and subsequent photoablation and mechanical debulking revealed that the mass was arising near the origin of the superior basal segment of the right lower lobe (RB6) and could be resected. Pathology confirmed this was consistent with the patient's known primary colon carcinoma. The potential for endobronchial metastasis in patients with colorectal carcinoma should be investigated in those patients with new or worsening pulmonary symptoms and signs.

Atorvastatin suppresses Toll-like receptor 4 expression and NF-κB activation in rabbit atherosclerotic plaques

BACKGROUND

Toll-like receptor 4 (TLR4) plays an essential role in the pathogenesis and progression of atherosclerosis, which overexpresses in atherosclerotic lesions and mediates the production of inflammatory factors. The aim of this study was to investigate the effects of atorvastatin on TLR4 protein and mRNA expression and its downstream factor NF-κB activation in rabbit atherosclerotic plaques.

MATERIALS AND METHODS

Rabbits continuously fed with high-fat diet for 24 weeks were randomly divided into two groups, the drug-treated group orally administrated with atorvastatin (2 mg/kg/day) three weeks after high-fat diet feeding and the model group with no treatment. The expression of TLR4 protein and mRNA, the level of activated NF-κB (p65) were respectively detected by western blotting, quantitative RT-PCR, and ELISA.

RESULTS

The results showed that atorvastatin treatment reduced the expression of TLR4 protein and mRNA by 24.1% (p < 0.05) and 46.9% (p < 0.01), respectively, and also inhibited NF-κB activation by 76.0% (p < 0.001) in the atherosclerotic plaques.

CONCLUSIONS

Thus, it was suggested that atorvastatin could exert an anti-atherosclerotic activity besides inhibiting cholesterol biosynthesis.

Role of pancreatic β-cell death and inflammation in diabetes

Apoptosis of pancreatic β-cells is the final step in the development of type 1 diabetes (T1D), leading to critically diminished β-cell mass and contributing to the onset of hyperglycaemia. The spontaneous apoptosis of pancreatic β-cells during pancreas ontogeny also induces cell death-associated inflammation, stimulates antigen-presenting cells and sensitizes naïve diabetogenic T cells. The role of pancreatic β-cell death in type 2 diabetes (T2D) is less clear. In the preclinical period of T2D, hyperinsulinaemia and β-cell hyperplasia develop to compensate for insulin resistance, which is clearly seen in animal models of T2D. For the development of overt T2D, relative insulin deficiency is critical in addition to insulin resistance. Insulin deficiency could be due to β-cell dysfunction and/or decreased β-cell mass. Pancreatic β-cell apoptosis due to lipid injury (lipoapoptosis), endoplasmic reticulum (ER) stress or JNK activation could contribute to the decreased β-cell mass in T2D. Activation of inflammasomes by lipid injury, ER stress, human islet amyloid polypeptide, hyperglycaemia or autophagy insufficiency could also lead to β-cell death or dysfunction. Thus, β-cell death and cell death-associated inflammation through innate immune receptors could be important in both T1D and T2D.

Frustrated tunnel ionization of noble gas dimers with Rydberg-electron shakeoff by electron charge oscillation

Strong field single ionization of homo- and heteronuclear noble gas dimers with ultrashort infrared laser pulses is experimentally investigated. A pronounced photoelectron yield maximum is found for dimers in the momentum range |p|≤0.1  a.u. which is absent for the corresponding monomer. This yield enhancement can be attributed to a new two-step strong field ionization mechanism active only in the dimers. In the first step, frustrated tunnel ionization at one of the atomic centers populates Rydberg states, which then become ionized in a second step through charge oscillation within the dimer ion core.

Noninvasive diagnosis of coronary artery disease using two parameters extracted in an extrema circle of magnetocardiogram

Magnetocardiography (MCG) is a complementary or alternative tool for noninvasive detection of coronary artery disease (CAD). The effectiveness of the tool for CAD diagnosis is generally evaluated by statistical analysis. In this study, we present a new method for screening CAD, in which two parameters including the curvature of magnetic field zero line and the area ratio of the extrema circle are extracted in magnetic field maps. 50 normal and 28 CAD subjects, whose signals were recorded by a 4-channel superconducting quantum interference device system, are analyzed with this method. The statistical results show a sensitivity and specificity of 71.4% and 72.0% respectively.

The significance of fragile histidine triad protein as a molecular prognostic marker of bladder urothelial carcinoma

OBJECTIVES

The role and clinical significance of fragile histidine triad (FHIT) gene in the pathogenesis of bladder urothelial carcinoma (UC) and the potential of Fhit protein as a prognostic biomarker for UC were investigated.

METHODS

FHIT expression was determined according to semiquantitative immunohistochemical staining for Fhit protein levels in normal bladder and bladder UC tissues. Associations between FHIT expression, clinicopathological features and survival were evaluated.

RESULTS

This study evaluated 42 cases of normal bladder and 125 cases of bladder UC; bladder UC cases had a median follow-up of 53.5 months. Immuno histochemistry showed that 95.2% of normal cases and 47.2% of bladder UC cases, respectively, were positive for Fhit protein; this difference was statistically significant. There was a significant association between negative FHIT expression in bladder UC and advanced tumour stage, high pathological grade, large tumour size, tumour recurrence and reduced survival time, but no association with age, gender, tumour number or tumour shape.

CONCLUSIONS

The FHIT gene may have an important role in the pathogenesis of bladder UC and was expressed at lower levels in bladder UC compared with normal bladder tissue. Using Fhit protein as a biomarker could provide important information about patient prognosis.

Autophagy deficiency in beta cells leads to compromised unfolded protein response and progression from obesity to diabetes in mice

AIMS/HYPOTHESIS

The unfolded protein response (UPR) in endoplasmic reticulum (ER) and autophagy are known to be related. We investigated the role of autophagy in UPR of pancreatic beta cells and the susceptibility of autophagy-deficient beta cells to the ER stress that is implicated in the development of diabetes.

METHODS

Rat insulin promoter (RIP)-Cre(+);autophagy-related 7 (Atg7)(F/W) mice were bred with ob/w mice to derive RIP-Cre(+);Atg7(F/F)-ob/ob mice and to induce ER stress in vivo. GFP-LC3(+)-ob/ob mice were generated to examine in vivo autophagic activity. Real-time RT-PCR was performed to study the expression of the genes of the UPR machinery. Proteolysis was assessed by determining release of incorporated radioactive leucine.

RESULTS

Production of UPR machinery was reduced in autophagy-deficient beta cells, which was associated with diminished production of p85α and p85β regulatory subunits of phosphoinositide 3-kinase. Because of compromised UPR machinery, autophagy-deficient beta cells were susceptible to ER stressors in vitro. When mice with beta cell-specific autophagy deficiency, which have mild hyperglycaemia, were bred with ob/ob mice to induce ER stress in vivo, severe diabetes developed, which was accompanied by an increase in beta cell death and accumulation of reactive oxygen species. The increased demand for UPR present in obesity was unmet in autophagy-deficient beta cells. Autophagy level and autophagic activity were enhanced by lipid, while proteolysis was reduced.

CONCLUSIONS/INTERPRETATION

These results suggest that autophagy is important for intact UPR machinery and appropriate UPR in response to lipid injury that increases demand for UPR. Autophagy deficiency in pancreatic beta cells may contribute to the progression from obesity to diabetes.

Structure effects in angle-resolved high-order above-threshold ionization of molecules

We present energy-resolved angular distributions of photoelectrons generated in above-threshold ionization (ATI) of nonaligned diatomic molecules N2 and O2 in high-intensity short laser pulses, with emphasis on the most energetic part of the spectra. The angular distribution for photoelectrons with energy of 10U(p) (U(p): ponderomotive energy), i.e., the plateau cutoff in ATI spectra, is found to be broader in O2 than in N2. Resorting to the analyses from both an S-matrix theory and an intuitive semiclassical model, we attribute the observation to the effect of the ground state molecular orbital structure on high-energy electron emission in strong-field molecular ionization.

Classical aspects in above-threshold ionization with a midinfrared strong laser field

We present high resolution photoelectron energy spectra of noble gas atoms from high intensity above-threshold ionization (ATI) at midinfrared wavelengths. An unexpected structure at the very low-energy portion of the spectra, in striking contrast to the prediction of the simple-man theory, has been revealed. A semiclassical model calculation is able to reproduce the experimental feature and suggests the prominent role of the Coulomb interaction of the outgoing electron with the parent ion in producing the peculiar structure in long wavelength ATI spectra.

Neurogenesis, migration, and apoptosis in the vomeronasal epithelium of adult mice

The location of neurogenesis and the direction of migration of neurons in the adult mouse vomeronasal organ is controversial. Cell division occurs at the center, and particularly, at the edges of the epithelium. Newly generated cells at the center of the epithelium participate in neurogenesis, however, it is unknown to what extent dividing cells at the edges participate in growth, become apoptotic or mature into neurons. Premitotic cells were labeled with bromodeoxyuridine (BrdU) in adult mice and animals allowed to survive for different postinjection periods. The terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick end-labeling (TUNEL) method was used to show the distribution of apoptotic cells. The vertical and horizontal position of BrdU-labeled cells was analyzed as a function of postinjection survival time. Vertical and horizontal migration of BrdU-labeled cells were detected. Cells in the central portions of the epithelium migrated vertically to become neurons as demonstrated by co-expression of olfactory marker protein. Cells at the edges migrated horizontally very slowly (less than 10% of the distance from the edge to the center of the epithelium per month), thus indicating that these cells participate in cell renewal exclusively in marginal regions. Neural turnover in the mouse vomeronasal epithelium, therefore appears to occur through a process of vertical migration. Data on the distribution of apoptotic cells indicate that a number of dividing cells throughout the epithelium, but particularly at the edges, die before becoming functional neurons. Accordingly, most dividing cells at the edges probably constitute a reservoir of stem cells dying before differentiation.

Passage of Harderian gland secretions to the vomeronasal organ of Thamnophis sirtalis (Serpentes: Colubridae)

The Harderian gland is a poorly understood structure found in the anterior orbit of most terrestrial vertebrates. In colubrid snakes it is a seromucous gland with a large postorbital portion. Numerous functions have been ascribed to this gland, including contributions to orbital lubrication or the vomeronasal system. Anatomically the Harderian gland is connected to the vomeronasal organ (VNO) via the nasolacrimal duct. In this study we traced the serous secretions of the Harderian gland of two subspecies of Thamnophis sirtalis (Colubridae), using autoradiographic techniques at the light-microscopic level. We injected the Harderian gland of the snakes with H3-proline either unilaterally (right side) or bilaterally. The right Harderian glands of both treatment groups were then injected with a potassium-rich solution. No labeling was observed in the orbital space of any treatment group, suggesting that the Harderian gland secretions of T. sirtalis do not function in orbital lubrication. Labeling was only observed in the right Harderian gland, Harderian gland ducts, nasolacrimal duct, apical vomeronasal sensory epithelium, VNO lumen, and vomeronasal duct. No such labeling was observed in any of the other treatments examined. Thus, the serous secretions of the Harderian gland in snakes flow to the VNO, and may be considered part of the vomeronasal system. The specific function of the Harderian gland secretions in the vomeronasal system remains to be determined.